The racing season is over for NASCAR driver Brian Vickers, who suffered from a type of blood clot known as deep vein thrombosis (DVT) last month.

Doctors have recommended that the 26-year old driver avoid racing for a minimum of six months.

"A blood clot is a dangerous thing," vascular surgeon Gilman Tyler M.D. told FOX News. "When you get a blood clot in your leg, one of the things it can do is break loose and go to your lung, and that’s called a pulmonary embolus. It is a significant health problem. It’s sort of surprising to me that we haven’t seen more of that in NASCAR because those guys probably get pretty dehydrated and they’re sitting in one position for hours at a time. I’m sort of surprised we haven’t heard of more of that because those are risk factors for sure."

Vickers called the pain he experienced from the clot "the most excruciating of his life."

Symptoms of DVT include swelling, gradual onset of pain, redness, warmth to the touch, leg cramps and a bluish or whitish discoloration of the skin, according to WebMD. Many DVT sufferers have no symptoms as well.

Natural ways to prevent blood clots include maintaining a healthy weight, avoiding prolonged periods of inactivity and keeping legs elevated while sitting or lying down.