8 Early Warning Signs of Parkinson’s Disease

3. Constipation

Parkinson’s affects the autonomic nervous system, which controls bodily functions we don’t normally think about, such as going to the bathroom. Parkinson’s might also affect the gut microbiome, according to a study published in the journal Neurology, which in turn affects how your digestion system functions — or doesn’t.

Parkinson’s doesn’t hit each gastrointestinal system the same way. A change in how often you have a bowel movement — or other digestion issues such as bloating, nausea and general discomfort — could be an early warning sign that should be investigated. A third of U.S. adults over age 60 report having constipation, so if you have this condition, mention it to your doctor, but there’s no reason to panic.

4. Anxiety/depression

Parkinson’s harms the brain’s ability to create serotonin and dopamine, two chemicals that affect mood. Changes in the levels of neurotransmitters can lead to increased anxiety and depression. According to the Parkinson’s Foundation, patients can experience depression or anxiety for two to five years before diagnosis.

Parkinson’s-induced mood disorder isn’t typically drastic, like major depression, Kilbane says. But a spouse or family member might notice a change — for example, when a normally happy person becomes a worrier.

“It’s so subtle that people may not go to the doctor,” she says.

5. Soft voice

According to the Parkinson’s Foundation, 89 percent of people with Parkinson’s will have speech and voice disorders. That often shows up first in their voice’s volume. A person may speak more softly without realizing it, Kilbane says, and a spouse, friend or family member has to ask the person to speak up and/or repeat himself.

6. Masked face

Parkinson’s affects muscles in the face, which experience the same gradual stiffening as the rest of the body. People with Parkinson’s will have “less facial mimicry and less spontaneous smiling,” says Kilbane, who calls this condition “poker face.”

People might think you’re angry or upset because your positive emotions are less likely to translate into a smile or other facial cues that show joy or appreciation.

7. Stiffness and gait problems

It’s common for undiagnosed Parkinson’s patients to view stiffness and gait problems as part of aging, Kilbane says. “You anticipate as you get older that you may slow down a bit in your movements, you might be a little stiffer and might shuffle a bit,” she says.

Stiffness from Parkinson’s can be mistaken for arthritis, but it will appear in the muscles, not the joints. It can be hard for a person to make that distinction without medical guidance, Kilbane says. Gait problems can show up in someone who has trouble keeping up with their peers on a walk or getting in and out of a car — again, something that might be attributed to old age. But both are signs of potential Parkinson’s.

8. Resting tremors

Shaking in the hand, foot or leg is often the first obvious visual sign of Parkinson’s, Tagliati says. By the time Parkinson’s affects muscles in this way, most patients have already experienced early signals such as sleep, smell and digestion problems — sometimes for years.

Involuntary movements are typically on one side of the body — not necessarily the dominant side — and occur when the limb is at rest. “Normally, when you use the hand, the tremor goes away,” Tagliati says. “Many people put [their] hand in [a] pocket, and nothing really happens.” A tremor in the chin is also common in Parkinson’s and should be investigated.

Editor's note: This story, first published May 4, 2022, has been updated to include new information.