The cholera vaccine used in the United States is an oral (swallowed) vaccine. Only one dose is needed.

Adenoviruses can cause illness that is usually mild, but can be serious in some cases.

An intestinal obstruction means that the small or large intestine is blocked at one or more spots. This prevents air, food, stool, and fluid from passing normally through the digestive system.

This procedure replaces a pacemaker or an ICD that is running low on battery power. The surgery is usually done as an outpatient procedure. You can go home the same day.

Hyperventilation syndrome is a pattern of breathing where you breathe more quickly and deeply than normal. This can be very upsetting. Here's what you need to know.

Hyperhidrosis is excessive sweating. It's often an ongoing (chronic) condition. Here's what you need to know.

Hidradenitis suppurativa is a long-term (chronic) skin disease. It causes painful bumps and sores to form around a hair follicle.

Heart palpitations are a symptom. It's the feeling you have when your heartbeat seems to be racing, pounding, skipping, or fluttering. Learn about what causes them and how they're treated.

Folliculitis is a skin condition that affects the hair follicles. It's often found on the neck, face, and scalp. Learn about causes, symptoms, and treatment.

First-degree heart block is a condition where the wiring of the heart is slow to send electrical signals for the heartbeat. Learn about its causes, symptoms, and treatment.