Some four million people in the UK are unable to urinate in public toilets because of a social phobia commonly called "shy pee", it is claimed.
Some four million people suffer from the problem in the UK
Experts have called on the medical profession to be more aware of the condition as sufferers can wait decades before seeking treatment.
The condition is caused by feelings of guilt, shame or embarrassment about urinating in public.
The British Psychological Society said many were reluctant to face the issue.
The BPS's Professor Alex Gardner, who addressed the society's Scottish conference this week, said it was also known as the Secret Phobia because people tried to cover it up.
"We need everyone to be more open about this. People are reluctant to even speak to their family about it.
"But it can destroy lives, people have left their jobs because of it.
"We also need medical professionals to become more aware, and address it."
Counselling, self-help groups and medication are all used to treat the condition, also known as bashful bladder and avoidant parures, which affects both men and women.
Australian research presented to the BPS conference in Perth showed that although nearly half of people sought treatment for the condition, many waited up to 30 years.
The number of sufferers was calculated by using studies carried out in the US and Canada which found between 7% and 10% of people suffered from the problem.
The International Paruresis Association said the condition most commonly occurred in public toilets, although sufferers could also have problems in homes of friends and even in their own home when they had visitors.