Medically reviewed by Shilpa Amin, M.D., CAQ, FAAFP, MSCP- Written by Jill Seladi-Schulman, Ph.D. - Updated on October 14, 2024

Key takeaways

• Both Alzheimer’s disease (AD) and Parkinson’s disease (PD) are neurodegenerative diseases that share similarities such as gradual onset, affecting older adults, and unusual protein accumulations in the brain, but they differ in symptoms, treatment, and risk factors.
• While there is no cure for either AD or PD, treatments are available to manage symptoms and improve the quality of life, including drugs and nondrug therapies like physical and occupational therapy.
• Key differences between AD and PD include that PD primarily affects movement, while AD mainly impacts cognitive functions like memory, communication, and reasoning. While older age and family history are risk factors for both, specific risks like pesticide exposure are more associated with PD.

Neurodegenerative diseases cause progressive damage to cells in the nervous system. These diseases can affect functions such as memory, behavior, and movement.

Alzheimer’s disease (AD) and Parkinson’s disease (PD) are two of the most common neurodegenerative diseases. While they share some similarities, they also have important differences.

What is Alzheimer’s disease?

AD is the most common type of dementia. Dementia is a progressive loss of cognitive function. This includes things such as thinking, memory, and problem-solving skills.

People with AD have abnormal accumulations of two proteins in their brains:

• beta-amyloid outside of nerve cells (amyloid plaques)
• tau protein inside of nerve cells (neurofibrillary tangles)

The underlying cause of these changes remains unknown. However, their presence is associated with the death of nerve cells, leading to the symptoms of AD.

What is Parkinson’s disease?

PD is a condition where nerve cells in a part of the brain involved in movement become damaged and begin to die, leading to progressive problems with movement.

PD may also lead to nonmotor symptoms and changes in memory, thinking, and behavior.

People with PD have accumulations of the protein alpha-synuclein in their nerve cells called Lewy bodies. Experts believe that Lewy bodies contribute in some way to the damage and death of nerve cells in PD.

Read more here: The Similarities and Differences Between Alzheimer's and Parkinson's

A columnist shares a notable glossary of Parkinson’s disease terminology

Written by Mollie Lombardi | March 2, 2026

When you are diagnosed with a chronic and complex disease like Parkinson’s, it can be like learning a new language.

Words like “gait” (the body’s posture while walking), “dyskinesia” (uncontrolled, involuntary movements affecting the arms, legs, head, or whole body), “micrographia” (tiny handwriting), and other strange-sounding words suddenly show up in everyday conversation. It can feel like you’re a walking medical encyclopedia, not a person.

I’ve been there. So, in the spirit of solidarity, I’ve put together my own glossary of Parkinson’s disease terminology to share with you. Here it goes:

Hitch in your Giddyup: This is when you just can’t walk right and start to shuffle or drag a foot behind you. Instead of smooth movement, it looks like you have sand in your gears. It happens when you have balance and gait problems and slow movements, also called bradykinesia. It’s also how my husband described the changes he’d seen in me when we met with a neurologist for the first time. Usage: “She’s got a hitch in her giddyup, doc!”

Halulus: I wish I could take credit for this one, but it’s from the Apple TV series “Shrinking.” The show tells the story of a multigenerational group of friends, one of whom has Parkinson’s disease. This character, played by Harrison Ford, has hallucinations, which the others fondly refer to as “halulus.”

Parkinson’s disease-related psychosis, which includes hallucinations, affects 20%-40% of people with Parkinson’s. Usage: “I hope if I have halulus someday, I’m in a bath with Jason Momoa.”

Read more here: A vocabulary lesson Parkinson's families will intimately understand

Grief is sneaky and comes in all shapes and sizes

Written by Christine Scheer | February 27, 2026

Grief has a way of slipping in when you least expect it. Generally, I am a cheerful person, but lately I’ve felt a bit … sad? Apathetic? Angry?

The correct answer is all of the above. Is it because I have Parkinson’s disease? Or was it triggered by the loss of our beloved dogs last month? I think I’m still grieving the loss of my old self, the person who was strong both physically and emotionally. Mostly, I am tired of not being strong enough to pick up my granddaughter.

According to the social network MyParkinsonsTeam, people with Parkinson’s may experience the five stages of grief: denial, anger, bargaining, depression, and acceptance. “The stages rarely happen in order,” the website notes, “and many people revisit some or all of the stages over and over after diagnosis.”

Reading about grief has made me reflect on how life has unfolded since my Parkinson’s diagnosis 11 years ago.

All shapes and sizes

Denial: Because another doctor had told me I didn’t have Parkinson’s, I had a hard time believing the neurologist when she told me that yes, I did have it. I asked her if she was sure, because I was certain it was a pinched nerve. I requested further testing. No pinched nerve, still Parkinson’s. For the past several months, I’ve had a lot of pain in my shoulder and arm, and guess what? It’s a pinched nerve, and it’s no fun at all.

Anger: Um, if anybody else mentions the keto diet as the key to curing myself, I might get violent. ‘Nough said.

Read more here: My experiences with the stages of grief since my Parkinson’s diagnosis

Medically reviewed by Nancy Hammond, M.D. — Written by Rachael Zimlich, RN, BSN — Updated on February 12, 2026

Key takeaways

• Stress, mood changes, and emotions such as anxiety and depression can worsen motor symptoms in people with Parkinson’s disease.
• Medications, especially levodopa, can cause complications and fluctuating responses. You may need dosage adjustments or additional treatments. Certain other medications can also aggravate Parkinson’s symptoms.
• Imbalances in gut bacteria and certain foods, such as processed foods and red meats, may affect the central nervous system and worsen Parkinson’s progression, while Mediterranean-type diets may help.

Parkinson’s disease is a chronic, progressive neurological disease. There’s no cure, and in the years after diagnosis, many people with this condition may notice their symptoms fluctuate or worsen.

What worsens Parkinson’s disease?

If you have Parkinson’s disease, there are various factors that may worsen your symptoms. Common triggers include the following.

Chronic stress

Research has identified chronic stress as one of the possible initial triggers for the onset of Parkinson’s disease.

In one survey in 2021Trusted Source, people with Parkinson’s disease reported increases in the following symptoms when their stress levels were higher:

• tremors
• movement problems
• sleep disturbances
• depression
• balance and gait
• dyskinesias like muscle weakness or twitching
• memory problems
• speech and communication difficulties

The study authors noted that tremors seemed to be the symptom most affected by stress.

Emotions

Stress, emotional turmoil, and other mood changes can have an effect on symptoms in people with Parkinson’s disease. Anxiety and depression are common emotional symptoms that often develop in those with the condition.

Research has found that motor symptoms were worse in people with Parkinson’s who were in a depressed, anxious, or otherwise emotional state.

Read more here: Common Triggers of Parkinson's Disease Symptoms