Patients with a degenerative condition are being subjected to a "frustrating and scandalous" standard of care when in hospitals, a charity has warned.
A hospital can be "one of the scariest places to be" for people who suffer from Parkinson's disease, according to a damning report from Parkinson's UK.
The charity said that patients are regularly denied life-altering medication when on a hospital ward, with some feeling as though they need to smuggle drugs into hospital.
A poll of 2,000 sufferers of the degenerative neurological condition found that 47% said that they had been denied regular access to the medication they needed to keep their condition under control while in hospital.
And 69% said they experienced "increased" levels of anxiety whilst in hospital because of the difficulties around getting their medication.
The charity said that understanding about the condition among hospital staff remains "woefully inadequate" after the survey also found that a third of sufferers believed that staff had a "poor understanding" of the importance of giving medication for the condition on time.
"Our research confirms that hospital - where people with Parkinson's should feel safest - can actually be the most dangerous place for them to be," said Parkinson's UK chief executive Steve Ford.
"Being admitted in hospital can be difficult enough, but when that is coupled with the fear and uncertainty of being deprived of your drugs - it can become unbearable.
"Time and again people tell us that they leave hospital with their Parkinson's in a far worse state than when they went in. Nurses tell us they receive an hour, at most, of specialised Parkinson's training and this fundamental lack of education has resulted in people with the condition being so terrified by their previous experiences in hospital that they use their wash bags to smuggle in their medication."
The charity, which released the report to coincide with Parkinson's Awareness Week, said the NHS should allow those with the condition who are able to take their medication themselves.
Parkinson's affects around 127,000 people in the UK. The main symptoms of the disease are tremors, slowness of movement and rigidity.
Dr Martin McShane, national clinical director for long-term conditions for NHS England, said: "The NHS must ensure people with Parkinson's get the right medication, at the right time, when they go into hospital.
"Any treatment and care of people with Parkinson's should take into account a patient's individual needs, whether in hospital or at home."