Q: Can you throw some light on thyroid tests and their reference ranges?

It’s key to understand the early signs and symptoms of your thyroid issues. Feeling cold all the time, difficulty in losing weight, constipation, low body temperature (anything lower than 97.6 F may be a sign of hypothyroidism), losing outer third of your eyebrow, high cholesterol in spite of a good diet, hairloss, irregular menses, poor immunity, low sex drive, difficulty in conceiving, severe PMS, acne, fluid retention, course hair, dry skin, fatigue, enlarged thyroid gland, chipping nails – you should get your thyroid checked.

[Diet changes to tackle thyroid problem]

Your blood work for thyroid should include the following tests: TSH; Free T4; Free T3; Reverse T3; Thyroid Peroxidase Antibodies (TPOAb); and Thyroglobulin Antibodies (TgAb)

TSH: TSH is the hormone that tells your thyroid to make more thyroid hormone. TSH test becomes worthless if your hypothalamus and pituitary are not doing their work well. You can’t rely on TSH alone, if you have symptoms. Regular reference range is 0.5 to 4.7 but in most cases above 2 means you will have symptoms and can treat this as a warning sign.

Free T4: Your thyroid makes mostly T4, also known as thyroxine. Thyroxine is the storage form of thyroid hormone – it circulates in the bloodstream before your tissues store it. When an area of your body needs energy, it gets converted into the active form, T3.

Optimal Free T4 range: 10-23 pmol/L (but above 11 means the imbalance has already started)

Free T3 – Triodothyroxine: When your tissues need energy, they convert T4 into Free T3, the active form. In some cases, your thyroid may be producing the hormone, but the body may not be converting it, resulting in hypothyroid symptoms. This is generally the reason your energy levels fizzle out midway in the gym. Above 5.5 pmol/L means thyroid function is moving towards hypo.

Reverse T3: If your metabolic rate is really slow or you’ve been following an ultra low-carb diet, check this level.

Antibodies (TPO + TG): If either one or both of these antibodies test high, it means your immune system is attacking the thyroid. That means you have one of two autoimmune thyroid diseases — Hashimoto’s thyroiditis if you’re hypothyroid, and Graves’ disease if you’re hyperthyroid.

TG should not be over 33 IU and TPO should be less than 9 IU.

Rashi Chowdhary is a nutritionist, diabetes educator and creator of The Protein Bake Shop. Got a problem? Our fantastic panel of renowned experts is available to answer all your questions related to fashion, well-being, nutrition, finance and hypnotherapy. Email your queries to friday@gulfnews.com.