Parkinson’s disease is a chronic, progressive disorder of the central nervous system. It develops when neurons in a region of the brain called the substantia nigra begin to deteriorate and die. These neurons produce dopamine, a chemical messenger that coordinates smooth, controlled movement. As dopamine levels fall, the brain loses its ability to regulate movement normally, leading to the tremors, stiffness, and slowness that characterise the condition.
Parkinson’s is not a single, uniform disease. It progresses at different rates in different people, and the combination of motor and non-motor symptoms varies widely from one patient to the next. It is most commonly diagnosed in people over 60, though early-onset Parkinson’s (before age 50) does occur.
Parkinson’s symptoms are broadly divided into motor symptoms (affecting movement) and non-motor symptoms (affecting other body systems). Both categories can affect daily life to a similar degree.
Motor symptoms:
Non-motor symptoms:
Non-motor symptoms are frequently underreported because patients and families may not connect them to Parkinson’s, but they can be just as disabling as the motor symptoms and should be addressed as part of treatment.
The exact cause of Parkinson’s disease is not fully understood. The underlying problem is the death of dopamine-producing neurons, but what triggers that process varies, and in many cases cannot be pinpointed. Current understanding points to a combination of factors:
In most patients, the disease is considered idiopathic, meaning no single identifiable cause can be isolated. It is likely the result of genetic susceptibility and environmental triggers accumulating over decades.
Parkinson’s disease develops gradually, and early symptoms are easy to dismiss. A slight tremor in one hand, feeling slower than usual, a stiff shoulder that doesn’t respond to stretching. These can be mistaken for normal ageing or attributed to other conditions.
Consult a neurologist if you notice:
Early diagnosis matters because treatment started in the early stages does more to manage symptoms and maintain functional independence. Waiting until symptoms are advanced limits what medication and therapy can achieve.
There is no single blood test or scan that definitively confirms Parkinson’s disease. Diagnosis is primarily clinical, based on a detailed neurological examination by a specialist experienced in movement disorders.
The neurologist will assess motor function (looking for the characteristic combination of tremor, bradykinesia, and rigidity), take a thorough history of symptoms and their progression, and evaluate how symptoms respond to dopaminergic medication. A positive response to levodopa is a strong indicator.
Diagnostic imaging is used selectively to support the diagnosis or rule out other conditions:
Diagnosis can be challenging in the early stages when symptoms are mild or atypical. In these cases, a period of clinical observation and repeat assessment may be needed before a confident diagnosis is made.
There is no cure for Parkinson's disease, but treatment can manage symptoms for many years. The goal is to maintain mobility, independence, and quality of life for as long as possible. Treatment is individualised and typically combines medication with physical therapy and, when needed, surgical intervention.
Medication is the foundation of Parkinson's treatment. The choice of drug, dosage, and timing is adjusted over time as the disease progresses and symptoms change.
Levodopa (with carbidopa): The most effective drug for Parkinson's motor symptoms. Levodopa is converted to dopamine in the brain, directly replacing the chemical that the disease depletes. It is usually combined with carbidopa, which prevents levodopa from being broken down before it reaches the brain. Most patients eventually need levodopa, and many start it early. Over years of use, its effect can become less smooth, leading to "wearing off" (symptoms returning before the next dose) and dyskinesias (involuntary movements at peak dose).
Dopamine agonists (pramipexole, ropinirole, rotigotine): These mimic dopamine's action in the brain. Sometimes used as initial therapy in younger patients to delay the introduction of levodopa, or added alongside levodopa to smooth out fluctuations. They carry a specific risk of impulse control disorders (compulsive gambling, shopping, or eating) that patients and families should watch for.
MAO-B inhibitors (rasagiline, selegiline, safinamide): Block the enzyme that breaks down dopamine in the brain, extending its availability. Used as early monotherapy for mild symptoms or added to levodopa to reduce wearing-off episodes.
COMT inhibitors (entacapone, opicapone): Prolong the effect of each levodopa dose by blocking another enzyme that degrades dopamine. Always used in combination with levodopa to reduce off-time.
Amantadine: Used primarily to manage levodopa-induced dyskinesias in later-stage disease.
Anticholinergics (trihexyphenidyl): Sometimes used for tremor-predominant Parkinson's in younger patients, though side effects (confusion, dry mouth, urinary retention) limit their use in older adults.
DBS is a surgical treatment in which thin electrodes are implanted in specific areas of the brain (usually the subthalamic nucleus or the globus pallidus interna) and connected to a pulse generator implanted in the chest. The device delivers continuous electrical impulses that modulate the abnormal brain signals causing motor symptoms.
DBS is considered for patients who have had Parkinson's for at least four to five years, still respond well to levodopa but experience motor fluctuations or dyskinesias that medication alone can no longer manage. It does not cure the disease or stop its progression, but it can reduce off-time, smooth out motor fluctuations, and lower medication doses. Not all patients are candidates: a thorough evaluation including neuropsychological testing is required before surgery.
Structured physical therapy is an essential part of Parkinson's management at every stage. It addresses the motor symptoms that medication alone cannot fully control and helps prevent secondary complications like falls, joint stiffness, and deconditioning.
Key areas include gait training and fall prevention, balance exercises, stretching and flexibility work to counter rigidity, speech therapy (specifically LSVT LOUD, a programme designed for Parkinson's-related speech problems), and occupational therapy to maintain independence in daily activities. Regular aerobic exercise (cycling, walking, swimming) has also been linked to slower motor decline in clinical studies, making it one of the few interventions with both symptomatic and potential protective benefit.
Depression affects roughly 40 to 50 percent of Parkinson's patients and is frequently undertreated. Anxiety, apathy, and cognitive changes also have a major impact on quality of life. Mental health care should be part of the treatment plan from the start, not an afterthought. Treatment may include antidepressants (SSRIs or SNRIs), counselling, cognitive behavioural therapy, and in some cases adjustment of Parkinson's medications that may be contributing to psychiatric symptoms.
Parkinson's disease is commonly described using the Hoehn and Yahr scale, which provides a general framework for tracking progression:
The rate of progression varies widely. Some patients remain at Stage 1 or 2 for many years with good symptom control, while others progress more quickly.
Parkinson's is a long-term condition, and how it's managed outside the clinic matters as much as what happens inside it.
A progressive neurological disorder caused by the loss of dopamine-producing neurons in the brain. It primarily affects movement (causing tremor, slowness, and stiffness) but also has non-motor effects on mood, sleep, cognition, and autonomic function.
Loss of sense of smell, constipation, REM sleep behaviour disorder (acting out dreams), and a slight tremor or slowness on one side of the body are among the earliest signs. These can precede the characteristic motor symptoms by several years.
Most cases are not directly inherited, but genetics play a role. Around 10 to 15 percent of cases have an identifiable genetic component. Having a first-degree relative with Parkinson’s increases risk but doesn’t make the disease inevitable.
Not at present. Current treatments manage symptoms but do not stop or reverse the underlying nerve cell loss. Research into disease-modifying therapies (including gene therapy, alpha-synuclein-targeting drugs, and GLP-1 receptor agonists) is active, but none have been proven effective yet.
It can. Mild cognitive changes (difficulty with planning, attention, and multitasking) are common. In later stages, some patients develop Parkinson’s disease dementia. Depression and anxiety are also frequent and should be treated alongside motor symptoms.
