Shaking in older adults usually comes from a type of tremor, and the most common cause by far is essential tremor, a condition where the hands, head, or voice shake during movement. Roughly 1.5% of people in their 70s and nearly 3% of those over 80 have essential tremor, and some studies suggest that close to 10% of people over 90 have noticeable shaking. Parkinson’s disease is the other well-known cause, but it accounts for far fewer cases. Several other conditions, medications, and even normal aging can also play a role.
Essential Tremor: The Most Common Cause
Essential tremor is the single most common reason older people shake. It causes a rhythmic trembling that shows up when you’re actively using your hands or arms, like pouring a drink, writing, or lifting a fork. The shaking typically stops or fades when your hands are resting in your lap. It can also affect the head, producing a nodding or side-to-side motion, and sometimes the voice.
Between 60% and 80% of essential tremor cases run in families, while the rest appear without any family history. Scientists believe it stems from mild dysfunction in the cerebellum, the part of the brain that coordinates movement. The condition tends to get more noticeable with age. Someone who had a barely perceptible hand tremor at 40 may find it significantly worse by 70 or 80, which is why many people first notice it in older relatives.
One reassuring finding: essential tremor on its own does not appear to cause the kind of progressive cognitive or physical decline seen in other neurological conditions. People with confirmed essential tremor actually performed as well as or better than control groups on tests of thinking ability and daily functioning in research studies.
Parkinson’s Disease Tremor
Parkinson’s disease causes a distinctly different kind of shaking. The tremor appears when a person is sitting still or standing with their arms relaxed, and it often looks like a slow, rhythmic pill-rolling motion in the fingers. The shaking actually decreases when the person intentionally moves their arms or legs, which is the opposite of essential tremor.
This happens because nerve cells deep in the brain gradually stop producing dopamine, a chemical the brain uses to initiate and control movement. As dopamine levels drop, the brain loses its ability to regulate certain motions. Parkinson’s tremor tends to start on one side of the body and is usually accompanied by other symptoms like stiffness, slowness of movement, and changes in walking.
A few practical ways to tell the two apart: Parkinson’s tremor typically gets worse while walking, while essential tremor gets better. Parkinson’s shaking tends to involve the fingers and wrist in a twisting motion, while essential tremor usually moves the wrist up and down. Parkinson’s tremor also vibrates more slowly, in the range of 4 to 6 cycles per second, compared to 5 to 8 cycles per second for essential tremor.
Medications That Cause Shaking
Drug-induced tremor is an underappreciated cause of shaking in older adults, partly because seniors tend to take more medications. Several common drug classes can trigger or worsen a tremor:
- Asthma inhalers containing albuterol or theophylline
- Antidepressants, including SSRIs and older tricyclic types
- Heart medications like amiodarone
- Mood stabilizers such as lithium
- Seizure medications like valproic acid
- Thyroid medication when the dose is too high
- Steroids
- Stimulants, including caffeine
The shaking from medications often looks like a fine, fast tremor in the hands and typically improves or disappears once the medication is adjusted. If a new tremor starts shortly after beginning a new prescription, that timing alone is a strong clue.
Normal Physiological Tremor
Everyone has a tiny tremor in their hands at all times. It’s usually invisible, but certain conditions can amplify it enough to notice. In older adults, this “enhanced physiological tremor” becomes more common and can be triggered by fatigue, anxiety, low blood sugar, too much caffeine, or even changes in body position. Physical exertion, like carrying groceries or exercising, can temporarily make it more pronounced.
Research shows that in older adults, changes in the cardiovascular system also contribute. Each heartbeat sends a small pulse of force through the body, and as arteries stiffen with age, this pulse can be transmitted more strongly to the limbs, making the hands shake slightly. This type of tremor is not a sign of disease. It comes and goes with the trigger and doesn’t get progressively worse over time the way essential tremor or Parkinson’s does.
Other Medical Causes
An overactive thyroid gland (hyperthyroidism) can cause tremor, though it often looks different in older adults than in younger ones. Younger people with hyperthyroidism typically have obvious shaking along with a racing heart, sweating, and hyperactivity. Older adults may instead present with what doctors call “apathetic” hyperthyroidism, where the classic signs of overactivation, including tremor, are muted or absent. This can make the condition easy to miss.
Vitamin B12 deficiency is another treatable cause. Because B12 is essential for nerve function, low levels can damage nerve pathways and produce shaking, particularly in the legs. In one documented case, a patient developed a rapid leg tremor that appeared only when standing and went away when sitting or walking. The tremor resolved completely after B12 supplementation and did not return even after other medications were stopped. B12 deficiency becomes more common with age because the stomach’s ability to absorb it declines.
Damage to the cerebellum from a stroke, a tumor, or long-term heavy alcohol use can produce a distinctive tremor that is slow and large, worsening as you reach toward a target. If someone’s hand shakes more and more as they try to press an elevator button or touch their nose, that pattern points to a cerebellar problem rather than essential tremor or Parkinson’s.
How Doctors Figure Out the Cause
The single most useful piece of information is when the shaking happens. A tremor at rest points toward Parkinson’s. A tremor during movement suggests essential tremor. A tremor only while standing raises the possibility of orthostatic tremor or B12 deficiency. Doctors will typically ask you to hold your arms out, touch your nose, draw a spiral, and walk across the room, watching how the tremor behaves in each situation.
They’ll also review your medication list, check thyroid function and B12 levels with blood tests, and look for other neurological signs like stiffness, slow movement, or balance problems. In uncertain cases, a brain scan that measures dopamine activity can help distinguish Parkinson’s from essential tremor, since dopamine levels are significantly reduced in Parkinson’s but only mildly affected in essential tremor.
One simple observation you can make at home: watch whether the shaking gets worse or better during a walk. In most Parkinson’s patients, the resting tremor increases while walking. In essential tremor, it decreases. That single detail, easy to spot in a parent or grandparent, can be genuinely useful information to bring to a doctor’s visit.