Shaky hands are common, and most of the time the reason is ordinary: too much coffee, a stressful day, a short night. A tremor can also come from a medicine, a drop in blood sugar, an overactive thyroid or a condition of the nervous system such as essential tremor or Parkinson's disease. This guide walks through the usual causes from the most to the least common, explains how doctors tell them apart, and lists the signs that should take you to a doctor or a neurologist. It cannot tell you which one you have; only an examination can.
A little shaking is normal
A tremor is an involuntary, rhythmic, back-and-forth movement of a body part. Everyone has a small, fast tremor, called physiological tremor. You normally cannot see it, but it shows up when you hold your arms out, carry a full cup or try to thread a needle.
According to the NHS, this normal tremor becomes more noticeable with age, stress, tiredness, anxiety or anger, and after caffeine, alcohol or smoking, or when you are very hot or very cold. When it is visible enough to notice, specialists call it enhanced physiological tremor, a category in the tremor classification of the International Parkinson and Movement Disorder Society (Bhatia and colleagues, 2018). It is not a disease; it is the normal tremor turned up by something in your body or your day.
Everyday triggers you can check yourself
| Trigger | What you might notice | What to try |
|---|---|---|
| Caffeine (coffee, energy drinks, strong tea) | Fine, fast shaking an hour or two after drinking | Cut down and see if it fades over a few days |
| Stress, anxiety, adrenaline | Shaking before a talk or after a scare, often with a racing heart | It settles when the stress passes; breathing slowly can help |
| Lack of sleep, fatigue | Less steady hands after a bad night or a long day | Compare on a rested day |
| Nicotine | Shakier hands after smoking or vaping | Notice whether it follows use |
| Cold | Shivering and stiff, trembling fingers | Warm up before judging |
| Hard exercise, gripping, lifting | Tired muscles tremble for a while | Rest and test again later |
| Alcohol withdrawal | A fine tremor with agitation, typically 24–72 hours after the last drink in heavy drinkers | This needs medical advice, not willpower alone |
A simple diary helps more than any single observation. Note when the shaking happens, what you ate, drank and took, and how you slept. If you want a number to compare, our hand tremor test gives a relative steadiness score on the same device each time.
Medicines that can cause shaking
Medicines are a common cause of tremor. The MSD Manual lists, among others, amitriptyline, beta-adrenergic medicines (such as some asthma inhalers), haloperidol, lithium, SSRI antidepressants, tamoxifen and valproate, as well as stimulants such as cocaine.
If your shaking started or got worse after a new medicine or a dose change, tell the doctor who prescribed it. Do not stop a prescribed medicine on your own; the NHS specifically advises speaking to your doctor first, and stopping some of these drugs suddenly can be dangerous.
Low blood sugar and an overactive thyroid
Low blood sugar (hypoglycaemia). Shaking is one of the typical signs, along with hunger, sweating, dizziness, a racing heartbeat and confusion. The NHS notes that it mainly affects people with diabetes who use insulin or some other diabetes medicines and is rare in people without diabetes. If you have diabetes and your hands suddenly shake, check your blood sugar and treat a low according to your plan.
Overactive thyroid (hyperthyroidism). The NHS lists twitching or trembling among its signs, together with a fast or irregular heartbeat, weight loss despite a bigger appetite, nervousness, irritability and feeling hot. A simple blood test of thyroid function can check this.
Essential tremor
Essential tremor is the most common tremor disorder in adults. In a meta-analysis of 28 population studies from 19 countries, Louis and Ferreira (2010) estimated that it affects about 0.9% of people of all ages and about 4.6% of people aged 65 and over.
Under the 2018 consensus criteria, essential tremor is an action tremor of both hands and arms that has been present for at least 3 years, with no other neurological signs such as stiffness or slowness. It may also affect the head or the voice. The MSD Manual describes it as a tremor that worsens slowly over many years, often runs in families and usually becomes smaller after a little alcohol. It is most noticeable when you use your hands: writing, drinking from a cup, using a key or a spoon.
Parkinson's tremor: shaking at rest
The tremor of Parkinson's disease behaves differently. The NHS describes it as shaking that usually begins in a hand or an arm and is more likely when the limb is relaxed and resting. It often starts on one side and may look like rolling a pill between the thumb and index finger. Tremor is only one sign; the main features are slowness of movement and stiffness, and handwriting may become smaller and walking shuffling.
| Essential tremor | Parkinson's tremor | |
|---|---|---|
| When it is worst | While using the hands or holding a posture | At rest, often less when the hand moves |
| Sides | Usually both hands | Often starts on one side |
| Other signs | None required (head or voice may shake) | Slowness, stiffness, small handwriting, shuffling walk |
| Family history | Common | Usually absent |
| After a little alcohol | Often smaller | No clear change |
These are tendencies, not rules. Tremors overlap, and other conditions, such as dystonia or multiple sclerosis, can also cause shaking.
How doctors tell tremors apart
Doctors first watch the tremor in three situations: with the hand resting in the lap, while holding the arms out, and during a movement such as touching the nose or drawing a spiral. They ask when it started, whether it runs in the family, which medicines you take, how much coffee and alcohol you drink, and whether there are other symptoms. Blood tests for thyroid function and blood sugar are common. Some people are referred to a neurologist, and in suspected Parkinson's a trial of medication may be part of the assessment.
An online test cannot do any of this. A browser samples your finger position at the screen's refresh rate, which is enough to see sway but not to measure tremor frequency or to tell rest tremor from action tremor. Our test is useful for one thing: comparing your own steadiness over time under the same conditions. Speed is a separate skill, which the finger tapping test and the reaction time test measure, and standing steadiness is covered by the balance test.
When to see a doctor or a neurologist
Make a doctor's appointment if your tremor:
- is getting worse over time or gets in the way of eating, drinking, writing or work (NHS);
- appears when your hand is resting, or mainly on one side;
- comes with stiffness, slowness, smaller handwriting, changes in walking or speech, or balance problems;
- started after a new medicine or dose change;
- comes with weight loss, a racing heart, sweating or feeling hot;
- affects your head or voice, or someone in your family has a similar tremor.
Your GP or family doctor can do the first assessment and refer you to a neurologist if needed.
Get urgent help (112 in Turkey and the EU, 999 in the UK, 911 in the US) if shaking comes suddenly with:
- weakness or numbness of the face, arm or leg on one side, or slurred speech: these can be signs of a stroke (the NHS FAST check: face, arms, speech, time to call);
- confusion, sweating and drowsiness in someone with diabetes who does not recover after taking sugar, or who becomes unresponsive;
- a head injury, or severe withdrawal symptoms after stopping heavy drinking.
Sources
- Bhatia, K. P., Bain, P., Bajaj, N., et al. (2018). Consensus Statement on the classification of tremors, from the task force on tremor of the International Parkinson and Movement Disorder Society. Movement Disorders, 33(1), 75–87.
- Louis, E. D., & Ferreira, J. J. (2010). How common is the most common adult movement disorder? Update on the worldwide prevalence of essential tremor. Movement Disorders, 25(5), 534–541.
- MSD Manual (Consumer Version). Some causes and features of tremor. msdmanuals.com
- NHS. Tremor or shaking hands. nhs.uk/conditions/tremor-or-shaking-hands
- NHS. Parkinson's disease: symptoms. nhs.uk/conditions/parkinsons-disease/symptoms
- NHS. Low blood sugar (hypoglycaemia). nhs.uk/conditions/low-blood-sugar-hypoglycaemia
- NHS. Overactive thyroid: symptoms. nhs.uk/conditions/overactive-thyroid-hyperthyroidism/symptoms
- NHS. Stroke: symptoms. nhs.uk/conditions/stroke/symptoms
Frequently asked questions
Why do my hands shake?
Most often because of a normal tremor that everyone has, made more visible by caffeine, stress, tiredness, nicotine, cold or hard exercise. Less often the cause is a medicine, low blood sugar, an overactive thyroid, essential tremor or Parkinson's disease. A doctor can tell them apart.
Is it normal for hands to shake a little?
Yes. Everyone has a small, fast physiological tremor. It becomes easier to see when you hold your arms out, after coffee, under stress or when you are tired. That alone is not a disease.
Can anxiety cause hand tremors?
Yes. Stress and anxiety release adrenaline, which makes the normal tremor more visible, often together with a racing heart. The shaking usually settles once the stress passes. If anxiety and shaking are frequent, talk to a doctor.
What is the difference between essential tremor and Parkinson's tremor?
Essential tremor usually affects both hands and is worst while you use them, for example when drinking or writing. Parkinson's tremor is typically worst at rest, often starts on one side and comes with slowness and stiffness. Only an examination can tell which one you have.
Can low blood sugar make your hands shake?
Yes. Shaking, sweating, hunger and a racing heartbeat are typical signs of low blood sugar. It mainly happens in people with diabetes who use insulin or some other diabetes medicines and is rare in people without diabetes.
When should I see a neurologist for hand tremors?
See a doctor if the tremor is getting worse, gets in the way of daily tasks, appears when your hand is resting or mainly on one side, or comes with stiffness, slowness, smaller handwriting or walking changes. Your doctor can refer you to a neurologist.
Can an online test diagnose a tremor?
No. A browser test can show how steady your finger or cursor is compared with your own earlier results, but it cannot measure tremor frequency or tell what kind of tremor you have. It is a self-check, not a diagnosis.