In-depth

Causes

Heart arrhythmias

Hyperthyroidism

Hyperthyroidism occurs when your thyroid gland produces too much of the hormone thyroxine — speeding up your metabolism and sometimes leading to serious complications.

Complications

Erectile dysfunction

Erectile dysfunction (ED) can be the result of physical or psychological causes or both. Discover what causes ED and what treatments are available.

Symptoms

Fatigue

Fatigue can signal many things. Here are some tips to help you decipher why you're wiped out and to regain your energy.

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.

Unexplained weight loss

Unexplained weight loss: Symptom — Overview covers possible causes of unexplained weight loss.

Tests and diagnosis

CT scan

A CT scan is an imaging test that uses X-rays to produce detailed images of the inside of your body.

MRI

MRI uses a magnetic field and radio waves to create detailed images of the organs and tissues within your body.

Treatments and drugs

Jul. 01, 2014

You Are ... The Campaign for Mayo Clinic

Mayo Clinic is a not-for-profit organization. Make a difference today.