Parkinson’s is caused by a loss of nerve cells in a specific part of the brain.
These nerve cells are used to help send messages between the brain and the nervous system.
Parkinson’s disease symptoms tend to develop gradually, and only appear as mild at first.
One of the more common warning signs of Parkinson’s is constipation.
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“Constipation is a common symptom of Parkinson’s that can cause discomfort and impact the benefit of Parkinson’s medications,” said the charity.
“It is one of the most persistent symptoms of Parkinson’s disease, arising often years before the motor symptoms and affecting people throughout their disease course.
“Constipation occurs when bowel movements, or ‘stools’ become less frequent or more difficult to pass.
“Some define constipation as less than three bowel movements per week, but what constitutes constipation can vary because our usual bathroom patterns differ. Some people go every day, while others may go only three or four times per week.”
Other common signs of Parkinson’s disease include tremors, slow movement, and muscle stiffness.
The muscle stiffness makes facial expressions more difficult, said the charity.
Tremors usually start in the hand or the arm, and are more likely to occur when the arm is relaxed.
There are about 127,000 people in the UK with Parkinson’s disease – the equivalent to about one in 500 people.