Anxiety, difficulty sleeping, fatigue and rapid heartbeat...is it stress or overactive thyroid symptoms? 

When the thyroid is out of whack, it affects the whole body. The thyroid gland may overproduce or underproduce hormones, and both conditions cause a host of sometimes-vague symptoms. But how do you know if you have hyperthyroidism, or overactive thyroid? Knowing the signs and symptoms of an overactive thyroid is the first step to get help and prevent more serious problems associated with the untreated condition. 

Function of the Thyroid Gland 

The thyroid is a butterfly-shaped gland located in the throat. It produces and secretes a hormone that regulates how the body uses energy -- its metabolism -- so any problems can affect all areas of the body. When the gland produces too little or too much of the hormone, it can cause a host of problematic symptoms. Only a doctor can tell you if your symptoms point to an overactive thyroid, so make an appointment for an examination and tests to get to the bottom of the problem. 

Hyperthyroidism affects millions of people -- many of whom are unaware. Overactive thyroid affects more women than men, specifically women older than age 60, according to a 2009 study published in the Journal of Clinical Endocrinology Metabolism. Having a family history of thyroid problems, being anemic, pregnant or having delivered a child within the past six months, eating too many iodine-rich foods and atrial fibrillation can increase the risk of hyperthyroidism, according to the National Endocrine and Metabolic Diseases Information Services. 

The most common condition associated with hyperthyroidism is Graves' disease, a condition in which antibodies stimulate the thyroid and may cause overproduction of thyroid hormone. Those affected by this disease may have bulging eyes. Nodules or lumps in the throat referred to as goiters are another sign of a malfunctioning thyroid gland. Some may experience thick skin over the shin. 

Despite how common hyperthyroidism is, it often goes unreported or misinterpreted. Patients may not see their doctors, believing the symptoms are a sign of a less serious condition. It's important to receive regular examinations and report any symptoms to your doctor. 

Symptoms of an Overactive Thyroid 

Symptoms can vary greatly from one patient to the next, so not experiencing any of the following symptoms does not mean that the patient has a normally functioning thyroid. A doctor should perform a complete examination and may perform other tests to diagnose hyperthyroidism. 

Some possible symptoms of hyperthyroidism include: 

• goiter (enlarged thyroid gland);
• nervousness or irritability;
• hair loss;
• thinning skin;
• depression and anxiety;
• shakiness or tremors;
• rapid heartbeat;
• insatiable hunger;
• weight loss (even if eating more);
• diarrhea;
• fatigue;
• higher body temperature;
• rash;
• infertility; and
• more. 

This is far from a complete list. If you experience these symptoms or others that might indicate an overactive thyroid, speak with your doctor right away for proper evaluation and diagnosis. 

Testing for Hyperthyroidism 

Knowing if you have an overactive thyroid may seem as simple as going through the checklist of symptoms, but the signs of overactive thyroid can mimic other conditions. 

A simple blood test will provide evidence of whether you have an overactive thyroid. The tests will look at thyroid-stimulating hormone levels, which will be low if the patient has hyperthyroidism. The tests will also look at levels of free thyroxine (Free T4), which will be higher in cases of hyperthyroidism. The blood tests may also look at triiodothyronine (T3) and thyroxine (T4) levels. But these tests may not be definitive.

For some, a specialist can perform a handful of tests to make a more accurate determination. This might include a scan of your thyroid using a radioactive substance so the doctor can get a picture of the thyroid. Your doctor can provide more information about the types of tests you might expect in order to determine whether you have an overactive thyroid. 

Treating an Overactive Thyroid 

The University of Maryland Medical Center explains that treatment will vary from patient to patient, depending on the extent of the condition, the type of hyperthyroidism, the patient's health, and other factors, including patient preference. 

Treatment may include an anti-thyroid drug that can reduce the thyroid hormone levels in the patient's blood. Some may use radioactive iodine to damage thyroid cells, which reduces thyroid hormone production. Other medications may take another approach; for example, beta-blockers block how the body uses thyroid hormone. 

Some patients may need lifetime thyroid treatment to keep hormone levels in check. Meanwhile, surgery to remove the part of the thyroid producing too much hormone may be part of some patients' treatment plans. 

Keep in mind that using anti-thyroid medication and treatment that reduces thyroid hormone levels may increase the risk of hypothyroidism, which is a condition characterized by low thyroid hormone levels in the body. So patients should discuss signs of hypothyroidism with their doctor when starting treatment and report any symptoms; the doctor may have to fine-tune treatment to alleviate symptoms.