One in five people with Parkinson's disease have had their symptoms mistaken for drunkenness by members of the public.
Research released at the start of Parkinson's Awareness week (15 -21 April) found there are high levels of discrimination against people with the disease, with four in ten sufferers reporting some form of misunderstanding at least once a month.
Parkinson's UK said the levels of prejudice are "unacceptable", with just under a quarter of people with the disease avoiding going out at busy times of the day over concern about people's reactions to their symptoms.
Around 127,000 people in the UK suffer from Parkinson's but awareness about the disease and its effects is lacking.
Parkinson's is a progressive neurological condition where sufferers do not have enough dopamine because specific nerve cells inside the brain have died.
Without the chemical dopamine, people find their movements become slower and it takes longer to do things. The main symptoms of Parkinson's are tremors, muscle stiffness and slowness of movement, but not all sufferers will experience all three.
Ward Stothers, 67, said: "It's a huge challenge every day trying to walk and I have to remind myself to be careful all the time.
"These days I feel anxious about going anywhere outside my home. My Parkinson's makes me trip a lot and if people push past me in the street I can easily lose my balance.
"It's hard to accept that this is happening to my body. But you have to keep picking yourself up, stay positive and just tell yourself you can get through it."
Ken Fenton, 66, added: "Some days I can walk into town without any problems at all, other times my legs just won't move at all.
"The general slowing down of life with Parkinson's is hugely frustrating. But I am determined not to give up.
"It's upsetting if you stare or think the worst. If Parkinson's makes me unsteady, please don't assume I'm drunk."
Steve Ford, chief executive of Parkinson's UK, said: "Time and again people with Parkinson's have to fight against the old stereotype that the condition is just a tremor.
"People have been refused service in shops and even shouted at in the street all because people have mistaken their speech or movement problems - common symptoms of the condition - for drunkenness.
"Life with Parkinson's can be unpredictable, with symptoms often changing on a daily, and even hourly, basis.
"Because of this many people risk being told they simply look 'too well' to have a disability, even shouted at for using a disabled bay in a car park. This simply has to change."