A man who suffered a stroke after getting his hair washed in a salon has been talking about his "life-changing injury".
Doctors who treated him said it was likely to have been a case of "beauty parlour syndrome" - which can occur when the neck is over-extended.
This can damage arteries, which can lead to a clot and then a stroke.
But the Stroke Association said the risk was "very small", and experts said hairdressers should use a cushion.
Dave Tyler, 45, told the Daily Mail that two days after he visited a salon in Brighton, he started having headaches and collapsed during a business meeting.
He also felt his body go numb.
Mr Tyler spent three months in hospital before learning to walk again with a stick, but he still can't drive and is often in pain.
Although he didn't feel any discomfort at the time his hair was being washed, he told BBC Radio 5 live that hairdressers should "be aware that something like this is possible".
He settled out of court and was paid £90,000 by the hairdressing salon in February.
The term "beauty parlour syndrome" has been used to describe this type of injury, which is rare.
Alexis Wieroniey, from the Stroke Association, said a stroke could be caused if the lining of an artery in the neck was torn.
If the carotid artery, which goes directly into the brain, is dissected or damaged, then blood clots can form over time and cause a stroke.
She said: "There is a very small chance that an injury might be caused by extending your neck back in a chair to have your hair washed, but no definitive link has been established between hair washing and strokes."
Pippa Tyrrell, professor of stroke medicine from the University of Manchester, said this type of whiplash injury was more likely to occur in road traffic accidents or when skiing, diving or bungee jumping.
And she said it was difficult to pinpoint when the damage was actually done.
"Someone might have had the injury before, already damaged the artery and only noticed it when they got their hair washed," Prof Tyrrell said.
She said carotid dissection could be a cause of stroke at any age and if anyone was suffering from headaches and neck pain down one side, they should see medical attention.
In 1997, medical journal The Lancet published a report on a 42-year-old woman who had had a stroke after having her hair washed.
In the report, two British doctors said the stroke had been due to damage to the right internal carotid artery, which had left her with numbness and slurred speech.
The doctors recommended that hairdressers used a cushion to make sure that the neck was not overextended.
In a small observational study in 2000, American doctors concluded that people who regularly suffered from pain and dizziness should be cautious about having a salon sink hair wash.
Earlier this year, a 48-year-old woman from California sued a hair salon after she suffered a debilitating stroke after getting her hair washed.
What is stroke?
A stroke is a brain attack that occurs when the blood supply to part of your brain is cut off.
Most strokes are caused by the blood supply to the brain being cut off, called an ischaemic stroke.
Strokes can also be caused by bleeding in or around the brain - a haemorrhagic stroke.
Blood carries essential nutrients and oxygen to your brain. And without them, brain cells can be damaged or die.
This damage can affect the way your body works as well as how you think, feel and communicate.