Allergies occur when your immune system has a reaction to a normally harmless foreign substance (known as an allergen) such as dust, pollen, or food, resulting in physical symptoms that can range from ...

Cardiac arrhythmias can produce a range of symptoms—from very mild, like lightheadedness, to life-threatening, including cardiac arrest. These can be divided into a “classic” group of symptoms that ...

People with HIV don’t usually have symptoms right away, so they may not know they have it. It can be years before HIV makes you feel sick. Please enter your age and the first day of your last period ...

Many people who get the virus that causes herpes never see or feel anything. If signs (what you see) or symptoms (what you feel) occur, a person may experience: Tingling, itching, or burning. Before ...

The most common herpes symptom are sores on your genitals or mouth. But most of the time there are no symptoms, so lots of people don’t know they have herpes. Please enter your age and the first day ...

What Are the Symptoms of Bronchitis? Your bronchial tubes, which carry air to your lungs, can get infected and swollen. When that happens, it’s called bronchitis. Symptoms of this condition ...

What are the signs and symptoms of scabies? After the mite burrows into the skin, it takes time to develop signs and symptoms. If you've had scabies before, the itching usually begins within one to ...

They spread in the same parts of the world and cause the same symptoms. But each virus reacts differently to antibodies — proteins your immune system makes to protect you against germs.