Checklist: Do You Have These Hyperthyroidism Symptoms?

What is hyperthyroidism?

Thyroid imbalances are common. Your thyroid might be underactive (hypothyroidism) or overactive (hyperthyroidism). As your thyroid regulates many of the systems in your body, an overactive thyroid can cause a variety of symptoms.

Hyperthyroidism happens when your thyroid makes more thyroid hormones than you need. These hormones then send parts of your system and metabolism into overdrive.

Mild hyperthyroidism might cause no symptoms, or you might think that your symptoms are normal. However, in most cases, hyperthyroidism does cause symptoms that, in some cases, can be life-threatening.

Hyperthyroidism can be caused by numerous factors, the most common being Graves’ disease, which can affect both your thyroid and your eyes. A few causes are transient, such as postpartum hyperthyroidism (caused by the stress of pregnancy on your system) or consuming too much iodine.

What are the risk factors for hyperthyroidism?

Known risk factors for hyperthyroidism include:

• Being assigned female at birth

• A family history of hyperthyroidism

• Routinely taking medication or supplements containing iodine, for example, some cough medicines and kelp seaweed supplements.

• Type 1 or type 2 diabetes

• Primary adrenal insufficiency¹

• Smoking

• Recent pregnancy

If these risk factors relate to you, it is important to monitor your thyroid hormone levels properly.

What symptoms should you look out for?

Note that all hyperthyroidism symptoms can also be caused by other conditions. You should talk to your doctor about hyperthyroidism if you have multiple symptoms and/or one of the risk factors listed above.

Hyperthyroidism can be eliminated with a simple blood test that checks for thyroid-stimulating hormone (TSH) levels.² If your levels are low, you may have hyperthyroidism. If they are high, you may have hypothyroidism. Further testing can then be done, including imaging of your thyroid gland.

Take a look at our checklist of potential hyperthyroidism symptoms:

1. Nervousness and anxiety: Having an overactive thyroid can make you feel jittery, "wired," or even paranoid.

2. Irritability: People with hyperthyroidism may be inclined to snap at others and not think about what they are saying.

3. Racing heart (tachycardia): Hyperthyroidism can cause your heart to beat too quickly. In some cases, you might not notice this, but it can cause chest pain, lightheadedness, fainting, and shortness of breath.

4. Hand tremors: Erratic or shaky movement of your hands and arms can be a sign of hyperthyroidism.³ However, hand tremors can be caused by a variety of conditions, some of them serious (such as Parkinson's disease). They can also happen without a cause (essential tremor).⁴

5. Difficulty sleeping: While we don't yet understand why, hyperthyroidism can cause sleep disturbance.⁵ You might take longer to fall asleep, have difficulty staying asleep, and be sleepy during the day. Other symptoms, such as hand tremors, may be bad enough to wake you up. Sleep disturbance can have other causes. For example, if you have elevated anxiety levels, you may not be able to quiet your mind enough to fall asleep.

6. Changes to your skin: The most common change is your skin becoming warmer and more moist.⁶ Other changes include altered skin pigmentation and pretibial myxedema. The latter is less frequent and causes discoloration of the skin around the feet, elbows, knees, upper back, and neck. It is most commonly associated with untreated Graves' disease.

7. Changes to your nails: This can include Plummer's nails, which are caused by the nail separating from the nail bed, most often on your fourth finger.⁷

8. Changes to your hair: Hyperthyroidism can cause diffuse hair loss (thinning all over the scalp) and the hair becoming fine and brittle.

9. Muscle weakness: This is a condition called ‘thyrotoxic myopathy,’ which results in eroding of the pelvic and shoulder muscles and temporary attacks of muscle weakness (periodic paralysis).⁸ This may display as weakness in your upper arms and thighs.

10. Bowel movements: More frequent bowel movements, but without diarrhea.

11. Weight loss: This is often associated with an increase in appetite. Sometimes a sufferer may see this as normal (or even desirable, given our society's focus on weight). Dieting can sometimes result in delayed diagnosis because you are trying to lose weight.

12. Changes to your menstrual cycle: A light menstrual flow, less frequent periods, and potentially reduced fertility. If you are having difficulty getting pregnant, it is worth getting your thyroid levels checked. There is also some indication the condition may lower male fertility.⁹

13. Excessive sweating: In some cases, this is localized to the palms and soles, in which case it is called ‘palmoplantar hyperhidrosis’.¹⁰

14. Swollen thyroid gland (a goiter): You may notice this if you examine your neck with your fingers. Your doctor might carry out a manual examination of the thyroid.

As already mentioned, all of these symptoms can be caused by other disorders or conditions. As TSH-level testing is quick and easy, doctors will often check your thyroid early in the process of trying to work out what is causing your symptoms. Therefore, it is worth bringing up the possibility of thyroid issues when you first talk to your doctor about one or more of these symptoms.

Most symptoms will resolve if your thyroid levels can be brought back down, although this can require long-term medication. It may also result in the need to intentionally reduce thyroid function through radiation or surgery, after which you must take supplementary thyroid hormones for life. These medications are safer for long-term use than those used to reduce thyroid levels.

When should you speak to a doctor?

If you have any of the symptoms in our checklist, you should talk to your doctor, especially if they are getting worse over time or are new to you. You should specifically bring up thyroid issues if any of the risk factors apply to you, such as having recently given birth.

In many cases, you will find that your symptoms are treatable, but it's vital to catch hyperthyroidism early. If untreated, an overactive thyroid can be debilitating and can lead to problems such as: 

• Heart failure

• Stroke

• Vision loss

• Infertility

The lowdown

About 1% of adults and teenagers in the US have an overactive thyroid.¹¹ In many cases, any apparent hyperthyroidism symptoms you may have are likely to be caused by a more common condition.

However, it's still vital to be checked out by a doctor. Whatever condition you have may be treatable, and if it is hyperthyroidism, it needs to be caught early to avoid progressive damage to your body.