Updated 20 July 2015

Answer: What's your diagnosis? – Case 19

Mrs L, a 40 year old lady, cannot lose weight despite all her efforts. Based on her symptoms, she most likely suffers from an underactive thyroid (hypothyroidism).


Mrs L has a long history of struggling to lose weight, persistent tiredness, being very sweaty most of the time and right wrist pain. Although some of the symptoms, like wrist pain, are not always present in a person suffering from an underactive thyroid, a history of cold intolerance, sweating and tiredness should always be evaluated for thyroid problems.

Effect on body temperature

The thyroid gland is the metabolic "brain" of the body. It controls metabolism. With an underactive thyroid, metabolism slows down, the body's temperature drops and one's heartbeat becomes slower. The energy needs of the body are also not met, causing a constant feeling of tiredness.   

The effect on body temperature will explain why Mrs L is intolerant to cold. Patients suffering from hypothyroidism will dress warmly when everyone else is wearing short-sleeves. The dryness of her skin, the fragility of her hair and mood change has little to do with winter, but are due to her underactive thyroid.

There are many causes for hypothyroidism, with inflammation of the gland (called Hashimoto's thyroiditis being the most common. The body launches an autoimmune response to the cells of the thyroid and subsequently the thyroid can not produce sufficient hormone. Other causes include certain medications like lithium, viral infections and deficiency of iodine (important to make thyroid hormone).

Read: Hashimoto's thyroiditis

The most important aspect of treating hypothyroidism is first to make the correct diagnosis. Based on your symptoms your doctor will already have some idea that you might suffer from an underactive thyroid. A blood test will confirm this. Generally two hormones are looked at: free thyroxine (T4) and TSH (thyroid stimulating hormone). In hypothyroidism, the T4 is generally low.

Pressure in carpal tunnel

Treating an underactive thyroid involves taking replacement hormone every day. This is a synthetic hormone that will help your thyroid function more efficiently. It is vitally important to have your thyroid levels checked on a regular basis to make sure the dosage of the medication is effective. Thyroid functions are usually checked about once every six months

Interesting fact: with hypothyroidism, there is increased pressure in the carpal tunnel due to fluid retention. This explains why patients may experience pain in the wrists. The symptoms usually disappear with treatment.

NOTE: Health24's on-site GP Dr Owen Wiese reveals new cases on Thursdays. The answer is posted with the story on Mondays, or you can get it in our Daily Tip – sign up here.

Previously on What's Your Diagnosis?

What's your diagnosis - Case 1: vomiting and weight loss

What's your diagnosis - Case 2: eye pain

What's your diagnosis - Case 3: strange behaviour and a bullet in the back

What's your diagnosis - Case 4: seeing odd things

What's your diagnosis - Case 5: mysterious lungs

What's your diagnosis - Case 6: runner with seizures

What's your diagnosis - Case 7: swollen knee

What's your diagnosis - Case 8: bloody semen

What's your diagnosis - Case 9: confusing neurological signs

What's your diagnosis - Case 10: diabetic teenager with unusual signs and symptoms

What's your diagnosis - Case 11:bruising with no apparent cause

What's your diagnosis - Case 12: severe tummy pain

What's your diagnosis - Case 13: severe sore throat

What's your diagnosis - Case 14:abdominal pain and swelling

What's your diagnosis - Case 15: the world is spinning

What's your diagnosis? – Case 16: numbness in forearm

What's your diagnosis? - Case 17: burning urine

What's your diagnosis? – Case 18: boy with persistent fever

Image: Thyroid pills from Shutterstock


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