Symptoms of Parkinson's disease differ from person to person. They also change as the disease progresses. Symptoms that one person gets in the early stages of the disease, another person may not get until later—or not at all.

Symptoms most often start between the ages of 50 and 60. They develop slowly. They often go unnoticed by family, friends, and even the person who has them.

The disease causes motor symptoms and non-motor symptoms. Motor symptoms are those that have to do with how you move. The most common one is tremor.

Tremor and other motor symptoms

Tremor, or shaking, often in a hand, arm, or leg, occurs when you're awake and sitting or standing still (resting tremor). It gets better when you move that body part.

• Tremor is often the first symptom that people with Parkinson's disease or their family members notice.
• At first the tremor may appear in just one arm or leg or only on one side of the body. The tremor also may affect the chin, lips, and tongue.
• As the disease progresses, the tremor may spread to both sides of the body. But in some cases the tremor stays on just one side.

Emotional and physical stress tends to make the tremor more noticeable. Sleep, complete relaxation, and intentional movement or action usually reduce or stop the tremor.

Tremor is one of the most common signs of Parkinson's. But not everyone with tremor has Parkinson's. Unlike tremor caused by Parkinson's, tremor caused by other conditions gets better when your arm or hand isn't moving, and it gets worse when you try to move it.

The most common cause of non-Parkinson's tremor is essential tremor. It's a treatable condition that is often wrongly diagnosed as Parkinson's.

Besides tremor, the most common symptoms include:

Stiff muscles (rigidity) and aching muscles.

One of the most common early signs of Parkinson's is a reduced arm swing on one side when you walk. This is caused by rigid muscles. Rigidity can also affect the muscles of the legs, face, neck, or other parts of the body. It may cause muscles to feel tired and achy.

Weakness of face and throat muscles.

It may get harder to talk and swallow. You may choke, cough, or drool. Speech becomes softer and monotonous. Loss of movement in the muscles in the face can cause a fixed, vacant facial expression, often called the "Parkinson's mask."

Trouble with walking and balance.

A person with this disease is likely to take small steps and shuffle with his or her feet close together. The person may bend forward slightly at the waist and have trouble turning around. Balance and posture problems may cause frequent falls. But these problems usually don't happen until later on.

Freezing.

This is a sudden, brief inability to move. It most often affects walking.

Non-motor symptoms

Parkinson's disease can cause many other symptoms that aren't related to how you move. These can be disabling. They may include things like constipation, sleep problems, and depression.

There are many other conditions with symptoms similar to Parkinson's disease. Some of these may be reversible.