In addition to the complications resulting from the symptoms of the disease, and medications for the disease, a variety of other complications can also result from Parkinson's. As such, the complications associated with Parkinson's Disease can be divided into the following categories:

 Complications Resulting from the Symptoms
 Complications Resulting from Medications
 Complications Resulting from Parkinson's

Each of these complication areas are discussed below.

Complications Resulting from the Symptoms

The signs and symptoms of Parkinson's Disease are:

 Tremors
 Slowed Motion (Bradykinesia)
 Difficulty Swallowing
 Rigid Muscles
 Loss of Automatic Movements
 Impaired Speech
 Dementia

There are a range of complications associated with Parkinson's which directly relate to the worsening of these symptoms as the disease progresses. Examples include tremors, difficulty coordinating movement, various movement and mobility issues, and speech problems. In some cases, people with Parkinson's may eventually develop dementia, a condition that can cause memory loss, impaired judgment, and personality changes.

Complications Resulting from Medications

The various medications and drugs used to treat Parkinson's Disease may cause a number of complications, including:

 Confusion
 Drop in blood pressure (especially when standing) (a condition called orthostatic hypotension)
 Dry mouth
 Hallucinations
 Involuntary movements (a condition known as dyskinesia)
 Liver damage / failure
 Memory loss
 Nausea
 Purple mottling of the skin
 Severe constipation
 Sleepiness
 Swollen ankles
 Urine retention - especially in men with an enlarged prostate

Complications Resulting from Parkinson's

One of the most common complications associated with Parkinson's is depression. Almost half of the people with Parkinson's develop depression, and, in some cases, depression can start months or years before Parkinson's is even diagnosed. This depression is caused by changes to the brain that are brought about by Parkinson's.

Other complications of Parkinson's disease include:

 Difficulty Chewing and Swallowing: In the later stages of Parkinson's, the mouth and throat muscles may be so affected that eating, chewing, and swallowing become quite difficult.

 Urinary issues: Some of the medications used to treat Parkinson's Disease may cause either urinary incontinence or urine retention. However, Parkinson's Disease itself cause the same problems independently of any medication.

 Constipation: Constipation can be a side effect of the medications used to treat Parkinson's. However, Parkinson's Disease itself cause the same problems independently of any medication because the digestive tract works more slowly.

 Sleep issues: People with Parkinson's often have trouble getting to sleep and staying asleep. During the night, they may be restless and may get up frequently. They may even act out their dreams, a condition that is called rapid eye movement sleep behavior disorder. Some of the problems with sleep may be associated with depression.

 Sexual Dysfunction: A decrease is sex drive and sexual desire is perfectly normal as people age. However, some people with Parkinson's may also notice a decreased sexual desire (libido). This may be caused by a combination of the psychological and/or physical factors associated with Parkinson's Disease.