Woman diagnosed with an allergy to exercise

A woman in the UK was recently diagnosed as "allergic to exercise."

Though it sounds like a great excuse to get out of gym class, the woman's condition is said to be potentially fatal.

Sweating and a rapid heartbeat cause Kasia Beaver's eyes to swell, her throat to close and hives on her body.

Beaver, 33, is one of just a few people ever diagnosed with an allergy to working out.

Oftentimes the allergy to exercise is accompanied by another allergy like peanuts or shellfish.

Her first attack occurred in her 20 after her first child was born.

It took several visits to specialists before the rare allergy was discovered.

Even simple tasks like taking care of her baby can trigger her allergy, which she now controls with medication.