Thyroid

The thyroid is not a vitamin or a mineral, but an underactive or overactive thyroid causes many of the same symptoms as deficiencies, so the questionnaire shows it as a separate card. Thyroid disease is several times more common in women than in men.

Symptoms

Underactive thyroid (hypothyroidism):

• tiredness, sleepiness;
• feeling cold, dry skin, constipation;
• hair loss, low mood, slowness.

Overactive thyroid (hyperthyroidism):

• feeling hot, sweating, trembling hands;
• a pounding heart, weight loss without trying;
• anxiety, irritability.

A single symptom means little. A combination matters, which is why the questionnaire shows the card only when three or more are present.

Who is at risk

• female sex;
• thyroid or other autoimmune disease in the family;
• the first year after giving birth;
• age around 60–65 and older;
• amiodarone, lithium, cancer immunotherapy, interferon;
• radiation to the neck or thyroid surgery.

Which test to ask for

TSH (thyroid-stimulating hormone) first. If it is abnormal, the lab or the doctor adds free T4. Thyroid antibodies (anti-TPO) only make sense after an abnormal TSH.

Pitfalls:

• biotin (“hair, skin and nails” products) can falsely change the result: tell the lab;
• do not test during an acute illness;
• a mildly abnormal result is usually repeated before anything is decided.

A swelling at the neck

Any new swelling at the front of the neck should be examined by a doctor. Trouble breathing or swallowing, a hoarse voice for weeks, or a hard, fast-growing lump need a doctor promptly.

Why not to take selenium, iodine or kelp “for the thyroid”

NICE does not recommend selenium or iodine for treating thyroid disease. Too much selenium causes hair loss and brittle nails, and too much iodine can harm the thyroid. If you take levothyroxine, iron, calcium and magnesium reduce its absorption: ask your doctor or pharmacist.