Signs and symptoms

A heart rate faster than normal; in an adult, more than 100 beats per minute.

A breathing rate faster than normal, above 20 breaths per minute in an adult.

Pain or discomfort that is felt when an area of the body is pressed or touched.

Involuntary muscle cramps and spasms that come from nerves firing too easily.

A buzzing or vibrating feeling felt with the fingertips over a blood vessel or the heart.

Inflammation of a vein with a clot in it, most often a superficial vein of the leg.

A sudden, life-threatening flare of hyperthyroidism, with high fever, a very fast heart rate, agitation and confusion.

Tingling or pins and needles felt where a nerve goes when the skin over that nerve is tapped.

A prickling, "pins and needles" feeling in the skin.

A ringing, buzzing, roaring or hissing sound in the ears that does not come from outside.

A sudden, sterile inflammation in the front of the eye after eye surgery, caused by a noninfectious substance that got into the eye.

Shaking of a part of the body, such as the hands, in small rhythmic movements that the person cannot control.

A group of three things, such as three signs that occur together.

A tight spasm of the jaw muscles that keeps the mouth from opening; also called lockjaw.

A spasm of the hand and wrist that appears when a blood pressure cuff on the upper arm is kept inflated for a few minutes.

Small, quick movements of a muscle or part of a muscle that happen without control.