Glossary

Find definitions for thousands of medical terms, treatments, and tests -- even health-related abbreviations, prefixes, and suffixes.

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Electrical pulses in the heart are controlled by special groups of cells called nodes. The SA (sinoatrial) node generates an electrical signal that causes the upper heart chambers (atria) to contract. The signal then passes through the AV (atrioventricular) node to the lower heart chambers (ventricles), causing them to contract, or pump.

The SA node is considered the pacemaker of the heart. Its electrical signals normally cause the atria to contract at a rate of 60 to 100 times a minute.

Disturbance anywhere along this electrical pathway can cause irregular heartbeats (arrhythmia).

Last Revised: August 9, 2012

Author: Healthwise Staff

Medical Review: Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & John M. Miller, MD, FACC - Cardiology, Electrophysiology

Sarcoidosis is a rare disease that causes inflammation and scar tissue throughout the body, especially the lungs, lymph nodes, liver, skin, and eyes.

The cause of sarcoidosis is not known. It occurs most often in young and middle-aged adults.

Symptoms may include fever, body aches, swelling of the lymph glands, breathlessness, a reddish rash on the face, painful joints, and numbness. But sometimes sarcoidosis does not cause any symptoms. It may lead to lung (respiratory) failure and heart problems in some cases.

Sarcoidosis may require long-term treatment (lasting months to years) with corticosteroids and other medicines, especially if it causes severe breathing problems or affects the brain and heart.

Last Revised: April 28, 2011

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Mark A. Rasmus, MD - Pulmonology, Critical Care Medicine, Sleep Medicine

Saturated fats are those that become hard at room temperature. They are found mostly in animal-based foods (such as meat, butter, milk, and cheese) and in coconut oil, palm oil, and cocoa butter.

Saturated fats should only be eaten in limited amounts because they harm blood vessels, which increases a person's risk for developing hardening of the arteries (atherosclerosis). Saturated fats also affect the levels of cholesterol in the blood and increase the risk of developing coronary artery disease.

Most of a person's fat calories should be from monounsaturated fats (such as from olive oil, peanut oil, avocados, and nuts) or polyunsaturated fats (such as from liquid vegetable oils, corn oil, or soybean oil).

Last Revised: January 25, 2013

Author: Healthwise Staff

Medical Review: Kathleen Romito, MD - Family Medicine & Rhonda O'Brien, MS, RD, CDE - Certified Diabetes Educator

Schizophrenia is a severe mental illness that can affect your ability to think clearly, manage your emotions, and interact with others. Most people who have it hear or see things that aren't there (hallucinations), believe things that aren't true (delusions), or think someone is trying to harm them (paranoia).

Schizophrenia is not the same as a "split personality" (dissociative identity disorder).

Last Revised: October 9, 2012

Author: Healthwise Staff

Medical Review: Kathleen Romito, MD - Family Medicine & Lisa S. Weinstock, MD - Psychiatry

Sclerotherapy is a nonsurgical treatment to get rid of varicose veins. A chemical called a sclerosant is injected into the varicose vein, causing it to close.

Sclerotherapy may be used to make spider veins and small varicose veins go away or become less visible. It is usually done only for cosmetic reasons because these types of varicose veins rarely cause symptoms or problems. It might be done along with other procedures to treat varicose veins.

Last Revised: February 1, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & David A. Szalay, MD - Vascular Surgery

Scoliosis is a problem with the curve in your spine. In scoliosis, your spine makes a large curve from side to side in the shape of the letter "S" or the letter "C." If this curve is severe, it can cause pain and make it hard to breathe.

Most cases of scoliosis are mild and don't need treatment. If your scoliosis is severe, you may need a brace or surgery.

Last Revised: October 9, 2012

Author: Healthwise Staff

Medical Review: John Pope, MD - Pediatrics & Robert B. Keller, MD - Orthopedics

Secondhand smoke is tobacco smoke that affects a nonsmoker. Secondhand smoke can come directly from a cigarette or other lit tobacco; it may also be exhaled by a person smoking.

Secondhand smoke is sometimes referred to as environmental tobacco smoke (ETS), involuntary smoking, or passive smoking.

Secondhand smoke contains the same cancer-causing and lung-damaging chemicals that affect smokers. Repeated exposure to secondhand smoke over many years can cause damage to a nonsmoker's lungs that is similar to that of a smoker's.

Secondhand smoke is the most important risk factor for cancer among nonsmokers, far greater than other known cancer-causing substances. Secondhand smoke is most harmful to:

  • Children and spouses of smokers, or anyone who lives with a smoker.
  • People who spend most of their time in confined areas that are filled with tobacco smoke.

Last Revised: September 12, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Michael Seth Rabin, MD - Medical Oncology

Sedatives and tranquilizers are medicines that have a calming effect. Generally, sedatives and tranquilizers depress or slow down certain body functions or the activity of an organ, such as the heart.

Mild sedatives and tranquilizers may be used to reduce anxiety or other nervous system problems, promote sleep, or regulate an organ system. For example, light doses of sedatives can help reduce coughing, nausea, or convulsions. Stronger doses of these substances may be used for severe sleep problems, severe anxiety, symptoms related to psychotic disorders (such as hallucinations or delusions), or as part of anesthesia. These types of sedatives and tranquilizers should only be used as directed by a doctor because they can become habit-forming. Abuse of some stronger substances can lead to severe health problems.

Last Revised: April 8, 2011

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Jerome B. Simon, MD, FRCPC, FACP - Gastroenterology

Seizures are sudden bursts of abnormal electrical activity in the brain that may affect a person's muscle control, movement, speech, vision, or awareness (consciousness). The effects of seizures depend on a person's individual response, as well as the seizure type, frequency, and severity.

Some seizures make a person fall to the ground in convulsions, in which the muscles stiffen or jerk out of control. Others may stare as if in a trance, have only a few muscle twitches, or sense a strange smell or visual disturbance not experienced by anyone else.

Sometimes a seizure is a symptom of another medical problem, such as a high fever (especially in children), a stroke, infection, low blood sugar (hypoglycemia), very low blood pressure, or a brain tumor.

Last Revised: August 26, 2011

Author: Healthwise Staff

Medical Review: Susan C. Kim, MD - Pediatrics & Steven C. Schachter, MD - Neurology

A child who is having severe difficulty breathing:

  • Cannot eat or talk because he or she is breathing so hard.
  • Has flared nostrils. Also, the child’s belly will move in and out with each breath.
  • Seems to be tiring out.
  • Seems very sleepy or confused.

Call 911 or emergency services if these signs are present.

Last Revised: January 10, 2012

Author: Healthwise Staff

Medical Review: William H. Blahd, Jr., MD, FACEP - Emergency Medicine & David Messenger, MD

Shingles is a painful skin rash caused by the same virus that causes chickenpox. After you've had chickenpox, the virus stays in your nerve tissue and can cause shingles later in life.

Shingles usually appears in a band, a strip, or a small area on one side of the face or body. It is also called herpes zoster.

Shingles is more common in older adults and people who have weak immune systems because of stress, injury, certain medicines, or other reasons.

Last Revised: December 18, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Christine Hahn, MD - Epidemiology

Shock is a life-threatening condition. Immediate medical care can make the difference between life and death.

Signs of shock (most of which will be present) include:

  • Passing out (losing consciousness).
  • Feeling very dizzy or lightheaded, like you may pass out.
  • Feeling very weak or having trouble standing up.
  • Being less alert. You may suddenly be unable to respond to questions, or you may be confused, restless, or fearful.

Also, a person in shock usually has an abnormal increase in heart rate and an abnormal decrease in blood pressure.

Shock may occur in response to a sudden illness or injury. When the body loses too much blood or fluids, the circulatory system can't get enough blood to the vital organs, and shock results.

Shock is a life-threatening condition. Immediate medical care is required any time shock is suspected.

  • Call 911 or other emergency services.
  • Have the person lie down. If there is an injury to the head, neck, or chest, keep the legs flat. Otherwise, raise the person's legs at least 12 in. (32 cm).
  • If the person vomits, roll him or her to one side to let fluids drain from the mouth. Use care if there could be an injury to the back or neck.
  • Stop any bleeding, and splint any broken bones.
  • Keep the person warm but not hot. Put a blanket under the person, and cover him or her with a sheet or blanket, depending on the weather. If the person is in a hot place, try to keep him or her cool.
  • Take the person's pulse in case medical staff on the phone need to know what the pulse is. Take it again if the person's condition changes.
  • Try to keep the person calm.

Last Revised: June 6, 2012

Author: Healthwise Staff

Medical Review: William H. Blahd, Jr., MD, FACEP - Emergency Medicine & H. Michael O'Connor, MD - Emergency Medicine

Sickle cell disease is a blood disorder in which the body produces an abnormal type of the oxygen-carrying substance hemoglobin in the red blood cells. Normal hemoglobin is called hemoglobin A, but people with sickle cell disease have only hemoglobin S, which turns normal, round red blood cells into abnormally curved (sickle) shapes.

Sickle-shaped blood cells are destroyed by the body faster than normal blood cells, which can result in an inadequate oxygen supply to the body (anemia). Most people with sickle cell disease have at least mild symptoms of chronic anemia, including:

  • Weakness and fatigue.
  • A pale appearance.
  • Yellowing of the skin and the whites of the eyes (jaundice).
  • Shortness of breath.

Sickle-shaped blood cells are also more likely to get stuck in and block small blood vessels throughout the body. Reduced blood flow caused by blocked blood vessels can damage certain organs, muscles, and bones. This may cause repeated episodes of pain (called sickle cell crises) that may last from hours to days. The pain most often occurs in the bones of the spine, arms and legs, the chest, and the abdomen.

People who have sickle cell disease need special medical care throughout their lives to treat the variety of problems that can be caused by the illness.

Last Revised: October 1, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Martin Steinberg, MD - Hematology

Sleep apnea is breathing that stops during sleep. The problem can be mild or severe, based on how often your lungs don't get enough air. This may happen from 5 to more than 50 times an hour.

The two main types of sleep apnea are obstructive sleep apnea, caused by blocked airways, and central sleep apnea, caused by a problem with how the brain signals the breathing muscles.

Sleep apnea can cause you to snore loudly. People with sleep apnea often have sleep problems and are tired during the day. And they are more likely to have high blood pressure and some heart problems.

Last Revised: October 9, 2012

Author: Healthwise Staff

Medical Review: Anne C. Poinier, MD - Internal Medicine & Mark A. Rasmus, MD - Pulmonology, Critical Care Medicine, Sleep Medicine

Social anxiety disorder means that you are so fearful about what you will say or do in front of other people that you avoid social settings like work or school. It's more than just being shy or nervous before public speaking. Counseling and sometimes medicines can help.

Last Revised: October 9, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Lisa S. Weinstock, MD - Psychiatry

Social workers are health professionals who use counseling to help people function in their environment, improve their relationships with others, and solve personal and family problems. They also help people locate and access appropriate resources for their particular needs.

A social worker may work in a hospital, community organization, or private counseling. Most social workers concentrate on a specific area of practice. For example, clinical social workers provide psychotherapy or counseling and a range of diagnostic services in public agencies, clinics, and private practice. Child or adult protective services social workers investigate reports of abuse and neglect and intervene if needed. And medical social workers provide counseling in hospitals, nursing homes, and rehabilitation facilities to people who are receiving therapy for physical problems or addictive behaviors.

Most social worker positions require a master's degree (MSW). But many social worker positions, such as a child protective services social worker, require a bachelor's degree (BSW) only. All 50 states require licensing, certification, and registration of social workers. Requirements vary from state to state.

Last Revised: August 17, 2012

Author: Healthwise Staff

Medical Review: Anne C. Poinier, MD - Internal Medicine & E. Gregory Thompson, MD - Internal Medicine

Sodium is a naturally occurring mineral that the body needs to function properly.

But too much sodium can cause problems, such as high blood pressure (hypertension) or heart failure, or make problems worse.

Salt is the most familiar source of sodium. Sodium is often hidden in foods that don't taste salty, such as cheddar cheese and processed foods. Sodium is also a major ingredient of monosodium glutamate (MSG), disodium phosphate, and baking soda.

Last Revised: July 12, 2012

Author: Healthwise Staff

Medical Review: Kathleen Romito, MD - Family Medicine & Rhonda O'Brien, MS, RD, CDE - Certified Diabetes Educator

Speech-language pathologists assess, diagnose, treat, and help prevent speech, language, and communication disorders.

Speech-language pathologists work with people who cannot make speech sounds or cannot make them clearly; have speech rhythm and fluency problems, such as stuttering; have voice quality problems, such as an inappropriate pitch or harsh voice; have problems understanding and producing language; have cognitive communication problems, such as attention, memory, and problem-solving disorders; or have oral motor problems that cause eating and swallowing difficulties. Speech pathologists work in hospitals, nursing homes, clinics, rehabilitation facilities, schools, and private practices.

A speech-language pathologist has a master's degree in speech and language and has completed postgraduate clinical work under the supervision of a licensed speech-language pathologist.

Speech-language pathologists can acquire the certificate of clinical competence in speech-language pathology (CCC-SLP) offered by the American Speech-Language-Hearing Association.

Last Revised: August 17, 2012

Author: Healthwise Staff

Medical Review: Anne C. Poinier, MD - Internal Medicine & E. Gregory Thompson, MD - Internal Medicine

Spider veins are small varicose veins that have a bluish, weblike appearance. Varicose veins are twisted and enlarged veins near the surface of the skin that most often occur in the legs and ankles.

Spider veins do not usually cause symptoms, although some people may feel mild itching or burning.

Spider veins are common and generally are not a serious health problem. Most people can manage varicose veins with home treatment, such as exercising, wearing compression stockings, and elevating the legs.

Other treatments include sclerotherapy, in which a chemical injection into a vein makes it close; or laser therapy, which scars and closes a vein. A closed vein loses its source of blood and dies. This makes it likely to fade or disappear.

Last Revised: February 1, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & David A. Szalay, MD - Vascular Surgery

Spinal discs are located between each of the 33 vertebrae, which are the interlocking bones of the spine that are stacked on top of one another. These discs act as shock absorbers for the spine and allow it to flex, bend, and twist.

The outer portion of a spinal disc, called the capsule (annulus fibrosus), is made of tough, elastic cartilage. The capsule surrounds a mass of jellylike material called the nucleus (nucleus pulposus).

Aging, injury, and illness can cause the spinal discs to crack or rupture. The jellylike nucleus can leak out, putting pressure on the spinal nerves. Pain, numbness, and weakness may result, and sometimes surgery is needed.

Spinal discs are also called intervertebral discs.

Last Revised: March 12, 2012

Author: Healthwise Staff

Medical Review: William H. Blahd, Jr., MD, FACEP - Emergency Medicine & Robert B. Keller, MD - Orthopedics

Spinal stenosis is the narrowing of the spinal canal. It can be caused by several problems, including overgrowth of bone or other tissue or by a herniated disc. When the spinal canal gets too narrow, it can squeeze and irritate your spinal cord or nearby nerve roots.

Spinal stenosis can cause pain, numbness, or weakness in your legs, buttocks, arms, or neck, depending on what area of your spine is affected.

Last Revised: October 9, 2012

Author: Healthwise Staff

Medical Review: William H. Blahd, Jr., MD, FACEP - Emergency Medicine & Robert B. Keller, MD - Orthopedics

Spinal tumors are growths that develop on the bones and ligaments of the spine, on the spinal cord, or on nerve roots. These tumors can be noncancerous (benign) or cancerous (malignant).

Malignant tumors rarely start in the spine. They are usually tumors that have spread from other parts of the body, particularly the breast, prostate gland, thyroid gland, or kidney.

Last Revised: May 16, 2011

Author: Healthwise Staff

Medical Review: Kathleen Romito, MD - Family Medicine & Howard Schaff, MD - Diagnostic Radiology

Angina happens when there is not enough blood flow to the heart muscle. This is often a result of narrowing of the blood vessels that supply blood to the heart. Angina symptoms include chest pain or pressure. But you might feel other symptoms like pain, pressure, or a strange feeling in the back, neck, jaw, or upper belly, or one or both shoulders or arms.

Stable angina occurs at fairly predictable times, usually with activity or exertion. It is relieved by rest and may continue without much change for years. Stable angina develops after a predictable amount of exertion or emotion and usually lasts 1 to 5 minutes.

A change in the usual pattern of stable angina means that the blood flow has become more impaired (called unstable angina). It is a warning sign that a heart attack may soon occur.

Last Revised: April 4, 2011

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & John M. Miller, MD, FACC - Cardiology, Electrophysiology

Stasis pigmentation is a brownish discoloration of the skin, often with swelling, that usually appears around the ankles. It results from blood cells breaking down and leaking out of tiny blood vessels.

Typically, stasis pigmentation occurs in people who have had varicose veins or other vein problems for many years.

Last Revised: February 1, 2012

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & David A. Szalay, MD - Vascular Surgery

Statins are a type of medicine used to treat high cholesterol. These medicines block an enzyme the body needs to produce cholesterol, thereby lowering the total amount of it in the blood.

Statins, also known as HMG-CoA reductase inhibitors, help reduce the risk of heart attack and stroke. Along with reducing cholesterol levels in the blood, statins reduce inflammation around the cholesterol buildup (called a plaque). By stabilizing the plaque, there is less risk that it will rupture and cause a blood clot that can lead to a heart attack or stroke.

Last Revised: June 29, 2012

Author: Healthwise Staff

Medical Review: Kathleen Romito, MD - Family Medicine & Robert A. Kloner, MD, PhD - Cardiology & Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology

A stent is a small, expandable tube that can be inserted into a blood vessel and expanded using a small balloon during a procedure called angioplasty. A stent is used to open a narrowed or clotted blood vessel.

When the balloon inside the stent is inflated, the stent expands and presses against the walls of the artery. This traps any fat and calcium buildup against the walls of the artery, allows blood to flow through the artery. The stent helps prevent the artery from closing again (restenosis). It can also help prevent small pieces of plaque from breaking off and causing a heart attack or stroke.

To insert the stent, a flexible, thin tube (catheter) is passed through an artery in the groin or arm into the narrowed artery. Then the balloon inside the stent is inflated.

Some stents, called drug-eluting stents, are coated with a medicine to more effectively prevent restenosis.

Last Revised: April 4, 2011

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & John M. Miller, MD - Electrophysiology

Strep throat is an infection in the throat and the tonsils caused by strep bacteria. It causes a severe sore throat and may cause a fever. It's treated with antibiotics.

Last Revised: October 9, 2012

Author: Healthwise Staff

Medical Review: Kathleen Romito, MD - Family Medicine & Donald R. Mintz, MD - Otolaryngology

Stress is what you feel when you have to handle more than you are used to. When you are stressed, your body responds as though you are in danger. It makes hormones that speed up your heart, make you breathe faster, and give you a burst of energy.

Some stress is normal and even useful. Stress can help if you need to work hard or react quickly. But if stress happens too often or lasts too long, it can cause health problems.

Last Revised: October 9, 2012

Author: Healthwise Staff

Medical Review: Kathleen Romito, MD - Family Medicine & Lisa S. Weinstock, MD - Psychiatry

A stroke happens when a blood vessel in the brain is blocked or bursts. Without blood and the oxygen it carries, part of the brain starts to die. Then the part of the body controlled by that area of the brain can't work properly.

Brain damage can start within minutes of a stroke. But quick treatment can help limit brain damage and increase the chance of a full recovery.

Last Revised: January 3, 2013

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Karin M. Lindholm, DO - Neurology

Stroke rehabilitation is training and therapy that helps a person regain function and relearn skills that were lost as a result of a stroke. The focus of rehabilitation depends on which part of the brain was damaged from the stroke and how much damage was done.

Rehabilitation begins in the hospital, as soon as the person is stable after having a stroke. A rehabilitation team that includes doctors and nurses and physical, occupational, speech, and recreational therapists helps the person to resume activities of daily living, such as eating, bathing, and dressing. Some people may need help learning how to walk again, communicate, and overcome disabilities from the stroke.

Last Revised: June 28, 2011

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Richard D. Zorowitz, MD - Physical Medicine and Rehabilitation

Sudden heart failure causes rapid fluid buildup, or congestion, in the lungs and other parts of the body. It occurs when the heart does not pump as much blood as the body needs.

Symptoms develop suddenly and include:

  • Severe shortness of breath.
  • An irregular or rapid heartbeat.
  • Coughing up foamy, pink mucus.

Sudden heart failure is an emergency medical situation and requires immediate care.

Last Revised: April 26, 2012

Author: Healthwise Staff

Medical Review: Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & Stephen Fort, MD, MRCP, FRCPC - Interventional Cardiology

Sudden infant death syndrome (SIDS) is the death of a baby who is younger than 1 year old without a known cause. Typically, a parent or other caregiver puts the baby—who seems healthy—down to sleep and returns later to find the baby has died.

No one is at fault when a baby dies of SIDS: it can be neither predicted nor completely prevented. A baby's death is not considered a case of SIDS when a specific cause is discovered, such as carbon monoxide poisoning. By definition, SIDS is considered the cause of a baby's death only when the death remains unexplained, even after a thorough investigation.

SIDS is also known as sudden infant death, unexplained (SIDU).

Placing babies on their backs when putting them down to sleep reduces the risk of SIDS.

Last Revised: May 16, 2012

Author: Healthwise Staff

Medical Review: John Pope, MD - Pediatrics & Chuck Norlin, MD - Pediatrics

A superficial venous thrombosis is a blood clot in a vein that is close to the surface of the skin. A superficial thrombosis usually forms a firm lump, sometimes like a rope, under the skin. Often the skin is red and tender. The skin may look infected, but an actual infection is not common.

If the area around the clot has inflammation, it is called superficial thrombophlebitis, or simply phlebitis.

Blood clots in superficial veins usually are not serious. Home treatment is typically all that is needed unless the clots are very painful or uncomfortable.

Last Revised: December 28, 2011

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Jeffrey S. Ginsberg, MD - Hematology

Supraventricular tachycardia (SVT) is a very fast heartbeat that happens from time to time because of a problem with your heart's electrical system. It may make you feel like your heart is racing, pounding, or out of rhythm. It usually isn't life-threatening, but you may need treatment.

Last Revised: October 9, 2012

Author: Healthwise Staff

Medical Review: Kathleen Romito, MD - Family Medicine

Surgeons are medical doctors who specialize in evaluating people who have potential surgical problems and performing surgical operations and techniques.

Common surgeries include hernia repairs, gallbladder removal, and removal of the appendix. There are many subspecialties in surgery, including chest (thoracic) surgery, blood vessel (vascular) surgery, and plastic surgery. Surgeons may further specialize by limiting their practice to specific age groups, such as pediatric surgeons, who only treat children.

Surgeons can be board-certified through the Board of Surgery, which is recognized by the American Board of Medical Specialties.

Last Revised: August 17, 2012

Author: Healthwise Staff

Medical Review: Anne C. Poinier, MD - Internal Medicine & E. Gregory Thompson, MD - Internal Medicine

Symptoms of a heart attack may include:

  • Chest pain or pressure, or a strange feeling in the chest.
  • Sweating.
  • Shortness of breath.
  • Nausea or vomiting.
  • Pain, pressure, or a strange feeling in the back, neck, jaw, or upper belly, or in one or both shoulders or arms.
  • Lightheadedness or sudden weakness.
  • A fast or irregular heartbeat.

The more of these symptoms you have, the more likely it is that you're having a heart attack. Chest pain or pressure is the most common symptom, but some people, especially women, may not notice it as much as other symptoms. You may not have chest pain at all but instead have shortness of breath, nausea, numbness, tingling, or a strange feeling in your chest or other areas.

If you have symptoms of a heart attack, call 911 or other emergency services immediately. After you call 911, the operator may tell you to chew 1 adult-strength or 2 to 4 low-dose aspirin. Wait for an ambulance. Do not try to drive yourself.

Last Revised: September 13, 2012

Author: Healthwise Staff

Medical Review: William H. Blahd, Jr., MD, FACEP - Emergency Medicine & David Messenger, MD

Symptoms of a stroke or transient ischemic attack (TIA) happen quickly. A stroke or TIA may cause:

  • Sudden numbness, tingling, weakness, or loss of movement in your face, arm, or leg, especially on only one side of your body.
  • Sudden vision changes.
  • Sudden trouble speaking.
  • Sudden confusion or trouble understanding simple statements.
  • Sudden problems with walking or balance.
  • A sudden, severe headache that is different from past headaches.

A stroke is an emergency and requires immediate medical attention.

Last Revised: January 3, 2013

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Karin M. Lindholm, DO - Neurology

Syncope is a loss of consciousness (fainting) that occurs when blood pressure drops very low and not enough blood reaches the brain. A person may have shortness of breath, palpitations, or chest discomfort before fainting.

The reduction in blood flow usually happens quickly, which causes symptoms to appear suddenly.

Syncope can be caused by several conditions, but it most often occurs when changes in heart rate or heart rhythm reduce the amount of blood flow to the body. Fainting caused by a problem in the heart is called cardiac syncope. Other types of syncope that are not linked with heart problems include neurally mediated syncope, also called vasovagal, neurocardiogenic, and vasodepressor syncope.

Syncope requires medical attention.

Last Revised: January 2, 2013

Author: Healthwise Staff

Medical Review: William H. Blahd, Jr., MD, FACEP - Emergency Medicine & David Messenger, MD

Syphilis is a sexually transmitted infection (STI) caused by the bacterium Treponema pallidum. The most common initial symptom is a painless sore called a chancre (say "shanker") that develops on the genitals.

Syphilis can be easily cured with antibiotics. If syphilis is not treated, it can eventually lead to serious health problems, such as blindness or heart problems.

Last Revised: September 29, 2011

Author: Healthwise Staff

Medical Review: Sarah Marshall, MD - Family Medicine & Devika Singh, MD, MPH - Infectious Disease

Systolic blood pressure refers to the pressure of blood in the artery when the heart contracts. It is the top (and higher) number in a blood pressure reading.

Diastolic blood pressure refers to the pressure of blood in the artery when the heart relaxes between beats. It is the bottom (and lower) number in a blood pressure reading.

For example, if a person's systolic pressure is 120 millimeters of mercury (mm Hg) and the diastolic pressure is 80 mm Hg, blood pressure is recorded as 120/80 and read as "120 over 80."

Last Revised: April 4, 2011

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Robert A. Kloner, MD, PhD - Cardiology

Systolic pressure is the pressure of blood against the artery walls when the heart has just finished contracting or pumping out blood. (Diastolic pressure is the pressure of blood against the artery walls between heartbeats, when the heart is relaxed and filling with blood.)

Systolic blood pressure is the upper number of a blood pressure reading. For example, if a person's systolic pressure is 120 millimeters of mercury (mm Hg) and the diastolic pressure is 80 mm Hg, blood pressure is recorded as 120/80 and read as "120 over 80."

Last Revised: April 5, 2011

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Robert A. Kloner, MD, PhD - Cardiology