Fernando Alonso has revealed that he has been struggling with headaches and lack of sensitivity in some limbs due to a compressed nerve.

The Ferrari driver, who will start sixth on the grid for the United States Grand Prix in Austin, said that doctors discovered problems with his left arm and leg following his fifth-placed finish in Abu Dhabi.

"After Abu Dhabi I was fine for three or four hours after the race, but when I did the medical check they found some lack of sensitivity in my left arm and leg and they were a little bit worried," AutoSport quotes the Spaniard as saying.

"I had a lot of headaches after, because a nerve was compressed and there was not enough blood pressure in my head. The nights were very difficult but slowly the inflammation came down.

"I had a little bit of pain yesterday and this morning when I woke up, but when you are in the car you forget it."

The two-time world champion is winning the battle for second place in the drivers' rankings.