9 Medical Reasons Why Your Hands Are Shaking

From too much coffee to potential brain damage, shaking hands are a symptom you—and your doctor—should take seriously.

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Why are you shaking?

Most people will deal with hand tremors at some point, and most often, it’s no big deal. However, shaking hands are always worth paying attention to because they can clue you into what’s going on with your physical and mental health.

What controls your hands

“Several areas of the brain are involved in the generation and control of movement of all extremities,” says Katerina Markopoulou, MD, neurologist and movement disorder specialist at NorthShore University HealthSystem Neurological Institute. These include the motor cortex in the frontal lobes of the brain, the basal ganglia (structures deep within the brain), and the brainstem (the connection between the brain and spinal cord), she explains.

Possible cause: Caffeine

If you’re overcaffeinated, you may find that your hands shake as you try to sort through the papers on your desk. Next time, curb your consumption. The FDA says that 400 mg of caffeine a day is acceptable, which is the amount found in four to five cups of coffee. Beyond that, you’re more likely to deal with side effects like jitters, insomnia, anxiousness, and a fast heart rate. The end of your shaking hands may be one of the 10 things that happen to your body when you quit coffee.

Possible cause: Hyperthyroidism

Your thyroid is a small gland in your neck that helps control many your heart, your digestion, your metabolism, and numerous other body functions. When your thyroid is running on overdrive—the rest of you is, too. Along with a heartbeat that feels as if it’s going to pound out of your chest and unintentional weight loss, you may also notice “a fine trembling” in hands and fingers, says the Mayo Clinic. A blood test can look at your thyroid levels; if they’re off, medications can keep this gland in check.

Possible cause: Medication side effect

This is what’s known as a drug-induced tremor—your nervous system is misfiring signals to your muscles due to a medication you’re on. There are many drugs that can trigger this problem, including antidepressants, blood pressure drugs, and asthma medicines, as well as inappropriate doses of thyroid meds. If you noticed shaking hands after starting a new medication, talk to your doctor.

Possible cause: Alcohol

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If you’ve abused alcohol, hand tremors can be a symptom of withdrawal. The shaking may occur because alcohol has altered your brain chemistry and is forcing your body to run on overdrive. The shakes may be at their worst 24 to 48 hours after your last drink and then gradually resolve within five days. If you are looking to cut back on alcohol, here are 17 tips to help you drink a little less.

Possible cause: Essential tremor

Nervous system disorders may also cause your hands to shake. One is called essential tremor, which causes “involuntary and rhythmic shaking” and is often genetic, according to Mayo Clinic. It’s most frequently seen in the hands, and as they point out, you may notice this during everyday tasks, like drinking from a glass. However, rest assured, this isn’t the start of Parkinson’s disease.

Possible cause: Mercury poisoning

Mercury poisoning is rare, but because it can be toxic to the nervous system, it’s one potential cause of tremors, according to the National Institute of Neurological Disorders and Stroke. If you’ve been exposed to enough mercury long-term to cause damage, you may also experience other serious symptoms, including problems walking, impaired memory, and blindness.

Possible cause: Social anxiety disorder

This disorder has physical manifestations—and including shaking hands when confronted by stressful situations (like public speaking or meeting people), according to the International Essential Tremor Foundation. For people with nerve disorders like ET, their shaking contributes to social anxieties, and the stress from these interactions makes tremors worse. Anxiety is a fast-growing diagnosis and becoming more and more common every day. These crisis counselors want everyone to know these 9 things about anxiety.

Possible cause: Stress or lack of sleep

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If you have a tremor condition like essential tremor, then lack of sleep or a stress overload will exacerbate the shaking. Follow essential sleep hygiene habits, and make sure you give yourself enough time to get a full night’s sleep. Also, pursue self-care measures that reduce your daily stress—exercise, deep breathing, meditation.

Possible cause: Parkinson’s disease

When people notice their hands are shaking, they often worry that Parkinson’s is the reason. This devastating disease will cause hand tremors—or hands that shake when relaxed or resting. “This tremor can appear by itself or with other signs such as stiffness, slowness of movement, or balance problems,” says Dr. Markopoulou. Unfortunately, Parkinson’s is only one of 10 surprising conditions your hands might predict.

What you should do

It’s one thing if you know you drank too much coffee and got the shakes. It’s another if you have no idea why you have shaking hands. “See a neurologist if you notice a tremor, especially if it worsens over time,” says Dr. Markopoulou. A neurologist who specializes in the treatment of movement disorders is the best option—ask your doctor for a referral.

Do I need an MRI?

You might. An MRI can’t diagnose Parkinson’s, says Dr. Markopoulou, “but it helps to exclude other conditions that may mimic Parkinson’s disease, such as a stroke or tumor in certain areas of the brain like the basal ganglia,” she says. If your doctors suspect Parkinson’s, she says, they might order a brain scan called DATSCAN to check the dopamine system of the brain to confirm a diagnosis.

Make your doctor visit count

The more info you have when you see your doctor, the better. Write down when your shaking hands happen, when they’re worst, any other symptoms you have at the same time, and how long you’ve been dealing with the issue, suggests Dr. Markopoulou. It isn’t just shaking you should be on the lookout for, your hands are sending you important messages about your health, including these 11 secrets.