In-depth

Acute coronary syndrome

Acute coronary syndrome occurs when there isn't enough blood flowing through your heart. It can be felt as chest pain (angina) or a heart attack.

Acute kidney failure

Acute kidney failure is the sudden loss of your kidneys' ability to filter waste from your bloodstream. Correcting the underlying cause increases the likelihood of recovery.

Acute lymphocytic leukemia

Acute lymphocytic leukemia is a type of leukemia that affects immature white blood cells. It's the most common cancer in children and adolescents.

Acute myelogenous leukemia (AML)

Acute myelogenous leukemia (AML), a form of cancer that affects the blood cells, is the most common type of leukemia.

Amniotic fluid embolism

Amniotic fluid embolism — Overview covers definition, symptoms and treatment of this pregnancy or post-pregnancy condition.

Angina

Angina is a common type of chest pain caused by coronary artery disease. Unstable angina can be a warning sign of a heart attack.

Aortic dissection

Aortic dissection occurs when blood leaks through a tear in the inner layer of the aorta. Left untreated, the condition is usually fatal.

Aortic valve regurgitation

Aortic valve stenosis

Aplastic anemia

Aplastic anemia occurs when your bone marrow stops producing enough new blood cells. It's a serious problem, but treatments are available.

ARDS

Acute respiratory distress syndrome (ARDS) is a sudden and serious lung failure that develops in people who are critically ill or have major injuries.

Asbestosis

Asbestosis is a lung disease resulting from prolonged exposure to asbestos, a product once commonly used in the building and manufacturing industries.

Ascariasis

Ascariasis is a common type of roundworm infection found worldwide. It's spread by poor hygiene and improper sanitation. Infections are effectively treated with medication.

Asthma

Asthma occurs when the main air passages of the lungs become inflamed, causing wheezing and difficulty breathing. Knowing warning signs can help you manage this chronic condition.

Asthma attack

Asthma attack: Find out what the symptoms are and how to treat an asthma attack.

Atrial septal defect

Atrial septal defect (ASD) is an abnormal opening between the heart's upper pumping chambers. It's common and readily treated.

Broken heart syndrome

Broken heart syndrome, also called stress cardiomyopathy, mimics a heart attack. Discover how stress could trigger this puzzling condition.

Carcinoid tumors

Carcinoid tumors are rare, slow-growing cancerous tumors that most often occur in the gastrointestinal tract or in the lungs.

Cardiogenic shock

Cardiogenic shock is a life-threatening complication usually of a heart attack. Cardiogenic shock treatments can be effective, but must be provided immediately.

Cardiomyopathy

Cardiomyopathy is a heart muscle disease. Treatment options depend on what type of cardiomyopathy you have.

Chest pain

Chest pain can be frightening, but it doesn't always indicate a heart attack.

Chronic cough

More than an annoyance, a chronic cough can significantly affect your quality of life. Find out how it's diagnosed and treated.

Chronic kidney disease

Chronic kidney disease, often caused by diabetes or high blood pressure, is the gradual loss of kidney function. Early detection and treatment can help.

Chronic sinusitis

Chronic sinusitis involves long-term inflammation or infection of the sinus cavities. Medications can help, and in rare cases surgery can treat this painful condition.

Churg-Strauss syndrome

Churg-Strauss syndrome is a rare disorder marked by blood vessel inflammation that affects organs throughout the body. Asthma is the most common sign.

Coarctation of the aorta

Coarctation of the aorta is a cardiovascular defect resulting in a narrowing of the aorta, the blood vessel that delivers oxygen-rich blood to your body.

Cystic fibrosis

Earlier detection and better treatments have improved the outlook for people with cystic fibrosis.

Diabetic coma

A diabetic coma is a medical emergency. Minimize the effects with prompt treatment.

Diabetic ketoacidosis

Diabetic ketoacidosis is a serious diabetes complication. Learn the warning signs — and know when to seek emergency care.

Dilated cardiomyopathy

Drug allergy

Drug allergy can occur with many medications. Find out what you can do to recognize and avoid potentially dangerous reactions.

Dust mite allergy

Dust mite allergy, an immune system reaction to inhaled dust mite "debris," causes hay fever symptoms and may cause allergy-induced asthma.

Ebstein's anomaly

Ebstein's anomaly is a rare heart defect. Some people may not have any symptoms, but others may need treatment, including surgery.

Egg allergy

Egg allergy can cause a serious reaction in children and adults. Here's how to recognize egg allergy symptoms, and what to do if a severe reaction occurs.

Eisenmenger syndrome

Eisenmenger syndrome, a complication of congenital heart defects, can be life-threatening if not properly treated. Find out more.

Emphysema

Tobacco smoke causes most cases of emphysema. Although quitting smoking can't reverse the damage, it can help keep this serious lung disease from becoming worse.

Enlarged heart

Enlarged heart is often a sign of a serious heart condition. Find out causes and treatments for enlarged heart.

Factor V Leiden

Factor V Leiden is an inherited disorder that results in an increased risk of blood clots. There's no cure, but blood-thinning medication can lower the risk of clotting.

Generalized anxiety disorder

Don't be a captive of your worries and fears. Control your anxiety by seeking treatment and learning coping skills.

Hantavirus pulmonary syndrome

Hantavirus pulmonary syndrome is initiated by a rodent-carried virus that infects the lung tissues, bringing on flu-like symptoms, respiratory problems and even death.

Heart arrhythmias

Heart attack

Heart disease

Heart disease, usually thought of as blockages in the arteries that can cause a heart attack, can describe any medical condition affecting your heart.

Heart failure

Heart failure means your heart can't efficiently pump blood throughout your body. Medications, and sometimes devices or surgery, can help you manage this condition.

Heart murmurs

This whooshing sound in your heart is usually harmless, but in some cases heart murmurs can alert your doctor to specific heart conditions.

Heart palpitations

Heart palpitations are skipped, fluttering or racing heartbeats that aren't usually a symptom of a serious heart problem. Discover the causes and symptoms of this condition.

HIV/AIDS

More than 39 million people are living with HIV — the virus that causes AIDS. Millions more are likely to become infected in the next decade.

Hurthle cell cancer

Hurthle cell cancer is a rare type of thyroid cancer. Surgical removal of the thyroid gland is usually required.

Hyperglycemia in diabetes

Hyperglycemia in diabetes — Comprehensive overview covers causes, symptoms and treatments of high blood sugar.

Hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy is a genetic disorder in which heart muscle becomes abnormally thick. It's the most common cause of sudden cardiac death in young people.

Iron deficiency anemia

Iron deficiency anemia may leave you feeling sapped of energy. This condition is especially common in women. Iron supplements usually help.

Left ventricular hypertrophy

Left ventricular hypertrophy, thickening of the wall of your heart's main pumping chamber, increases your risk of cardiovascular diseases.

Legionnaires' disease

Legionnaires' disease, a severe form of pneumonia, is caused by bacteria that can live in water in air conditioning systems, showers and spas.

Lung cancer

Smoking increases your risk of lung cancer. Quit now and reduce your risk.

Lupus

Lupus is a chronic disease that can affect your skin, joints and organs. With proper care, most people with lupus live relatively active, healthy lives.

Menorrhagia

Mesothelioma

Mesothelioma is a type of cancer closely linked to asbestos exposure. Find out the signs and symptoms of malignant mesothelioma and how to protect yourself.

Mitral valve prolapse

Mitral valve prolapse occurs when the valve separating two of your heart's chambers malfunctions. The disorder usually isn't serious and often doesn't require surgical treatment.

Mitral valve regurgitation

Mitral valve stenosis

Myelodysplastic syndromes

Myelodysplastic syndromes are a group of blood cell disorders that can cause anemia, fatigue, serious bleeding problems and recurrent infections.

Myelofibrosis

In myelofibrosis, healthy bone marrow is replaced with scar tissue, leading to severe anemia and fatigue.

Myocardial ischemia

Myocardial ischemia is a heart problem that occurs when blood flow to your heart muscle is decreased, reducing the heart's oxygen supply.

Myocarditis

Myocarditis is a disease in which the heart muscle becomes inflamed and swollen, often as the result of an infection.

Ovarian hyperstimulation syndrome

Ovarian hyperstimulation syndrome (OHSS) — Comprehensive overview covers symptoms, treatment of this complication of infertility treatment.

Panic attacks

Panic attacks can make you feel like you're having a heart attack. Learn how to manage these intense bursts of fear.

Peanut allergy

Peanut allergy can be serious. Find out what you need to know to prevent a life-threatening reaction.

Pericardial effusion

Pericardial effusion, the accumulation of excess fluid in the sac-like structure around the heart, can decrease heart function and can be life-threatening.

Pleurisy

Pleurisy is the painful inflammation of the membranes that surround your lungs. The cause can be one of a number of underlying conditions.

Pneumonia

There are at least 50 kinds of pneumonia — a serious lung infection that takes the lives of more than 60,000 Americans every year.

Pneumonitis

Pneumonitis is a general term for lung inflammation. It can cause difficulty breathing, often accompanied by a cough.

Pneumothorax

A pneumothorax, which is a partial or complete collapse of a lung, can result from a chest injury, lung disease or certain medical procedures.

Polycythemia vera

Polycythemia vera is a rare blood disorder in which a person's bone marrow makes too many blood cells.

Polyhydramnios

Polyhydramnios — Comprehensive overview covers symptoms, causes and treatment of excessive amniotic fluid in pregnancy.

Pulmonary atresia

Pulmonary atresia is a heart defect that you're born with. Fortunately, treatment soon after birth and ongoing throughout childhood and adulthood greatly improve your prognosis.

Pulmonary embolism

Pulmonary embolism occurs when one or more arteries in your lungs become blocked. Surgery, cancer, family history and long airplane trips may place you at risk.

Pulmonary fibrosis

Pulmonary fibrosis results from scar tissue that forms in your lungs. This affects your ability to breathe and obtain enough oxygen.

Pulmonary hypertension

High blood pressure affecting only the arteries in your lungs is known as pulmonary hypertension. Discover the symptoms, risk factors and treatment for this condition.

Pulmonary valve stenosis

Pulmonary valve stenosis is a narrowing of the valve that controls blood flow from your heart to your lungs. It's usually present at birth.

Rheumatic fever

Rheumatic fever, an inflammatory disease triggered by untreated or poorly treated strep throat, can cause permanent heart damage.

Sarcoidosis

Sarcoidosis starts in your lungs but can cause inflammation in any part of your body. It can last a lifetime, or disappear in a few years.

Sleep apnea

Sleep apnea causes people to repeatedly stop breathing during their sleep. Common signs of this sleep disorder include loud snores punctuated by periods of silence.

Sleep apnea, central

Central sleep apnea is an uncommon condition that occurs when your brain has problems controlling your breathing during sleep.

Sleep apnea, obstructive

Obstructive sleep apnea is the most common type of sleep apnea — a condition that causes you to repeatedly stop breathing while you sleep.

Small vessel disease

If you have symptoms of heart disease, but your doctor doesn't see any blocked major arteries, small vessel disease may be the cause.

Spontaneous coronary artery dissection

Find out about this rare cause of heart attack in young, healthy people.

Sudden cardiac arrest

Sudden cardiac arrest is a medical emergency. Rapid treatment improves your chances of survival.

Tachycardia

Tachycardia, a rapid heart rate, is caused by an abnormality in your heart's electrical impulses. Tachycardia can cause serious complications, including sudden cardiac arrest.

Tetralogy of Fallot

Tetralogy of Fallot, a cause of "blue baby" syndrome, is a congenital heart condition resulting in oxygen-poor blood leaving the heart and entering the body.

Thalassemia

Thalassemia is an inherited blood disorder, characterized by less hemoglobin and fewer red blood cells than normal. When necessary, treatment includes blood transfusions.

Thoracic aortic aneurysm

Thyroid nodules

Most thyroid nodules — lumps in the thyroid gland — cause no problems. But nodules that affect swallowing, produce excess thyroid hormone or are malignant require treatment.

Transposition of the great arteries

Transposition of the great arteries is a congenital heart defect in which the placement of the aorta and the pulmonary artery is switched.

Tricuspid atresia

A heart with tricuspid atresia doesn't have a tricuspid valve. This heart defect prevents blood flow from the right atrium to the right ventricle.

Tuberous sclerosis

Tuberous sclerosis is a rare genetic disease. With appropriate treatment, many people who have tuberous sclerosis lead full, productive lives.

Ventricular fibrillation

Ventricular fibrillation is a life-threatening heart rhythm disturbance that requires immediate treatment. Find out more.

Ventricular septal defect

A ventricular septal defect (VSD) is an abnormal opening between the heart's lower chambers. Untreated, this congenital defect may cause heart failure and pulmonary hypertension.

Vitamin deficiency anemia

Lacking certain vitamins can lead to vitamin deficiency anemia. Find out which vitamins are linked to this condition.

Von Willebrand disease

Von Willebrand disease is an inherited bleeding condition caused by a deficit in or impairment of a protein essential for blood clotting.

Wegener's granulomatosis

Wegener's granulomatosis is an uncommon disease that causes blood vessel inflammation that can damage lungs, kidneys and other organs. Untreated, it can be fatal.

Wolff-Parkinson-White syndrome

An abnormal electrical pathway in the heart causes the rapid heart rate of Wolff-Parkinson-White syndrome.

Apr. 13, 2013