Psychiatric symptoms such as depression or mania can be caused by a number of medical illnesses. Thyroid storm is a rare condition that may initially be thought to be a psychiatric disorder. Thyroid storm is an extreme form of hyperthyroidism (excessive thyroid hormone), which is usually brought on by some form of stress such as an infection or trauma.
Thyroid storm is characterized by a variety of symptoms that may be initially thought to be due to a psychiatric illness such as bipolar disorder because of manic-like symptoms such as severe restlessness. Agitation is quite common and may be thought to be due to drug or alcohol intoxication.
However, the presence of other signs and symptoms may alert a physician that they are dealing with a thyroid storm. These symptoms include change in level of consciousness, confusion, seizures, vomiting, diarrhea, abdominal pain, sweating, dehydration, very rapid pulse, low or high blood pressure, and/or heart rhythm abnormalities. Not all of these signs and symptoms are to be expected in any given patient.
Such patients have untreated hyperthyroidism and may not even know that they have it. There are tests that can support the diagnosis of thyroid storm including elevated thyroid hormone levels. The excess of these hormones can cause abnormalities in various organs such as the kidneys, liver and heart. It is one of the causes of congestive heart failure (the heart cannot pump enough blood to meet the body's needs).
Thyroid storm is a medical emergency and patients with a constellation of many of these symptoms should go to a nearby emergency department. Since it is rare and the individual symptoms are not unique to this condition, the diagnosis may not be thought of during an initial evaluation.
Milder forms of hyperthyroidism can be confused with an anxiety disorder since such patients often feel anxious due to the metabolic effects of excessive thyroid hormones. Unintended weight loss despite eating well, diarrhea, tremor, rapid heart rate, irritability, sweating, fatigue, brittle hair, muscle weakness, and menstrual disturbances are all potential symptoms of hyperthyroidism.
On the other hand, low thyroid (hypothyroidism) can mimic depression and should be considered in the differential diagnosis of depression. Other symptoms of low thyroid include cold sensitivity, constipation, dry skin, weight gain, hoarseness,muscle weakness, painful joints, thinning hair, slow heart rate, memory problems, heavy menses, and elevated cholesterol.
Excessive or inadequate thyroid hormone levels are easy to measure with blood tests. Additional tests may be needed to identify specific causes since there are a variety of reasons why a thyroid may over or underproduce thyroid hormone. There are unusual cases where a patient secretly takes thyroid hormone in order to try to lose weight or to feign illness.
The bottom line is that thyroid disease is common and fairly easy to identify with common lab tests. Thyroid storm is a rate manifestation of excessive thyroid hormone that can be life threatening. Too much thyroid hormone and too little thyroid hormone can both present as psychiatric illnesses and must be distinguished from them.
