Parkinson’s disease is probably best known for its effects on movement. The most apparent symptoms are rigid limbs, slowed movements, and shaking. Less well-known are the complications that occur because of various symptoms — like depression, sleep disorders, and dementia.

Whether you’ve been diagnosed with Parkinson’s, or you have a loved one with the disease, here are 11 complications you should be aware of so you can watch for the warning signs.

1. Anxiety and depression

It’s normal to feel anxious or upset when you live with a chronic condition like Parkinson’s disease. Yet depression is more than just a byproduct of living with this disease. It can be a direct result of the disease because of chemical changes in the brain. Parkinson’s may contribute to depression through its effects on the hormone serotonin, which regulates mood.

Up to half of the people with Parkinson’s disease have clinical depression at some point in their lives. If you feel down or you’ve lost interest in life, talk to your doctor. Antidepressants and therapy can help relieve your depression.

2. Difficulty swallowing

Parkinson’s weakens the muscles in your mouth and jaw that help you chew and swallow food. As a result, food can get stuck in your throat. In the later stages of Parkinson’s, trouble swallowing can make you choke, or allow food and liquids to leak into your lungs and cause pneumonia.

Some people with Parkinson’s produce too much or too little saliva. Excess saliva can lead to drooling. Too little saliva can make swallowing uncomfortable.

If you have trouble swallowing, see your doctor. A speech-language pathologist can teach you techniques to help foods and liquids go down more easily.

3. Dementia

Although Parkinson’s is mainly a movement disorder, it can also disrupt parts of the brain that control thought and memory. Between 50 and 80 percent of people with Parkinson’s develop abnormal protein deposits called Lewy bodies in their brains. These are the same deposits found in people who have dementia with Lewy bodies (DLB).

Dementia in Parkinson’s disease causes symptoms like:

  • memory loss
  • trouble concentrating
  • poor judgment
  • hallucinations (seeing things that aren’t real)
  • delusions (false ideas)
  • irritability
  • sleep disturbances
  • anxiety

These symptoms can start several years after the onset of Parkinson’s. Some of the same medications that treat Alzheimer’s disease and other forms of dementia also help with Parkinson’s dementia.

4. Sleep disorders

Sleep disorders are common in people with Parkinson’s disease. Any of these nighttime issues can disrupt your sleep:

  • trouble falling asleep (insomnia)
  • nightmares
  • acting out dreams (REM sleep behavior disorder)
  • restless legs syndrome (RLS)
  • sleep apnea
  • frequent need to urinate at night (nocturia)
  • confusion at night

A sleep specialist can diagnose these issues, and recommend treatments to help you sleep more soundly.

5. Bladder and bowel problems

Trouble controlling urination and bowel movements stems from a problem with messages getting from your brain to your bladder and bowels. Bladder and bowel problems related to Parkinson’s disease include:

  • a constant urge to urinate (urge incontinence or overactive bladder)
  • leaking when you laugh, exercise, or sneeze (stress incontinence)
  • frequent need to urinate at night
  • weak urine stream
  • constipation
  • diarrhea
  • stool leakage (fecal incontinence)

Making a few lifestyle changes can help improve bowel and bladder issues. For example:

  • Go to the bathroom at regular times throughout the day.
  • Increase your fiber and fluid intake.
  • Take a stool softener.

See your doctor for an evaluation. Medications and other treatments can help relieve incontinence due to Parkinson’s.

6. Involuntary movements (dyskinesia)

This complication isn’t caused by Parkinson’s disease, but by the medication used to treat it. People who take high doses of the drug levodopa (or who stay on it for many years) can develop uncontrolled movements such as head shaking, twitching, swaying, or fidgeting. These movements are called dyskinesia.

Shifting dopamine levels in your brain cause dyskinesia. When you take levodopa, dopamine levels rise. As the drug wears off, levels drop. Changing your levodopa dose or adding in an extended-release formula drug may help prevent this complication. Speak with your doctor if you take levodopa and are experiencing dyskinesia.

7. Fatigue

Difficulty sleeping at night — which is common in people with Parkinson’s disease — can make you feel tired during the day. But Parkinson’s fatigue isn’t your ordinary exhaustion. Some people feel so tired they can barely get out of bed. Taking naps, exercising, and taking your medication as prescribed can all help combat this Parkinson’s complication.

8. Pain

About 10 percent of people with Parkinson’s experience pain as their first symptom. Up to 50 percent of people diagnosed with the disease will experience pain at some point.

A number of factors in Parkinson’s disease trigger pain. Causes include muscle contractions and abnormal processing of pain signals in the brain.

The pain can be centered in your:

  • shoulders
  • neck
  • back
  • feet

It can feel:

  • aching
  • burning
  • sharp
  • like pins and needles
  • pulsing

Levodopa — the same drug used to manage Parkinson’s symptoms — can also help with pain. It relieves the muscle spasms that trigger pain.

Other pain treatments include:

  • analgesic pain relievers
  • physical therapy
  • acupuncture
  • exercise, including tai chi and yoga

9. Blood pressure swings

You might notice that you get a little dizzy whenever you stand up from a seated or lying position. This symptom is called orthostatic or postural hypotension. It’s caused by a drop in blood pressure when you change positions. It affects about 1 in 5 people with Parkinson’s.

Your body has an internal mechanism that adjusts your blood pressure whenever you move. Postural hypotension happens when there is a problem with this mechanism. Some Parkinson’s medications can also cause a drop in blood pressure.

To avoid sudden drops in blood pressure:

  • Move slowly when going from a seated or lying position to standing.
  • Drink eight glasses of water each day (extra fluid increases blood pressure).
  • Ask your doctor if you need to adjust the dose of any medications that could be affecting your blood pressure.

10. Impaired sense of smell

A reduced sense of smell is a common — but often overlooked — early symptom of Parkinson’s disease. Researchers think it’s due to nerve damage from the abnormal buildup of the protein alpha-synuclein (or α-synuclein) in parts of the brain that control the sense of smell.

11. Reduced sex drive

Parkinson’s damages the nerves that enable men to have an erection and provide feeling to the genitals. It also causes stiff or jerky movements, which can make the act of having sex uncomfortable.

As a result, up to 80 percent of people with Parkinson’s disease lose the desire — or the ability — to have sex. Your doctor can help you find ways to work around sexual issues due to Parkinson’s disease.