Question

A 35 year old woman comes to her primary care provider with the chief complaint of severe insomnia. She states that it is very difficult for her to fall asleep and stay asleep. She says she has lost 18 pounds over 4 months. She now has a BMI of 19. She seems nervous and is easily irritable. She is afebrile, has a heart rate of 106 per minute, blood pressure of 146/78 and respiratory rate of 20. Her eye examination reveals mild strabismus and lid lag. There are no palpable neck masses, although her thyroid gland seems somewhat enlarged and nontender. Her hands are sweaty and have a fine tremor. Her reflexes are very brisk. She takes no medications other than her daily multivitamin. Her CBC and serum electrolytes are within normal limits. Serum TSH is 0.1 mIU/L (Normal range: 0.4 – 4.2).   

1. What is your presumptive diagnosis?
2. Which signs and symptoms lead you to your presumptive diagnosis?
3. How do you interpret the TSH results?
4. What is the differential diagnosis?
5. How would you confirm your diagnosis?

Answer 1

Presumptive diagnosis is hyperthyrodism

The patients low levels of TSH, enlarged thyroid (overactive thyroid) symptoms of insomnia, weight loss, low respiratory rate, brisk reflexes, sweaty hand are all classic symptoms of hyperthyrodism.

A low TSH indicates that your thyroid is overactive and producing excess thyroid hormone. If the thyroid gland is secreting levels of hormones that are too high, the pituitary gland produces less TSH. On the other hand a high TSH indicates the thyroid is underactive and producing less hormones.(T3 or T4)

A diffrential diagnosis means that there is more than one possibility for your diagnosis, or it is the process of differentiating between two or more conditions which share similar signs or symptom. Graves disease is an example of diffrential diagnosis for hyperthyrodism.

A high level of thyroxine and low level of TSH indicative of an overactive thyroid, which could confirm diagnosis of hyperthyrodism.