Thyroid deficiency (hypothyroidism): what to watch for and what to do

Feeling tired, cold, and slow despite normal sleep? Those are classic signs of thyroid deficiency—also called hypothyroidism. The thyroid controls metabolism, and when it underperforms you can get fatigue, weight gain, dry skin, hair loss, constipation, heavy periods, and higher cholesterol. If several of these match what you’re experiencing, don’t guess—get a blood test.

How hypothyroidism is diagnosed and treated

Your doctor will usually order TSH and free T4. High TSH with low or low-normal free T4 points to primary hypothyroidism. Anti-TPO antibodies suggest Hashimoto’s, an autoimmune cause. Treatment almost always means levothyroxine, a synthetic T4 hormone. Typical starting dose for a healthy adult is about 1.6 mcg per kg per day, but many people start lower. Older adults and those with heart disease often begin at 25–50 mcg daily.

Take levothyroxine on an empty stomach—30–60 minutes before breakfast or at bedtime at least three hours after your last meal. Wait 6–8 weeks after a dose change to recheck TSH; that’s how long levels usually settle. Most people reach a stable dose after a few adjustments. Targets vary: many doctors aim for TSH roughly 0.5–3.0 mIU/L for most adults, but your doctor may individualize that based on age, symptoms, and other health issues.

Daily tips, drug interactions, and saving money

Certain supplements and meds reduce levothyroxine absorption. Take iron, calcium, antacids with aluminum or magnesium, and some cholesterol binders at least four hours apart from your thyroid pill. Soy and high-fiber meals can also interfere if taken right after the pill. If you use calcium or iron regularly, schedule them away from your thyroid dose and tell your prescriber—lab numbers can look wrong if timing is off.

If you’re pregnant or planning pregnancy, tell your doctor—thyroid needs often rise early in pregnancy and doses are adjusted quickly. Symptoms alone don’t prove anything; lab monitoring matters.

Want to save on meds? Generic levothyroxine is widely available and works for most people, but check with your prescriber before switching brands—sometimes a small dose tweak and recheck are needed after a brand change. If buying online, always use a licensed pharmacy, require a prescription, and avoid sites that ship without one. Look for clear contact info, verified reviews, and secure checkout. Extremely low prices that don’t ask for a prescription are red flags.

If symptoms persist despite normal labs, ask about adherence, timing of pills, interactions, and rare causes like central hypothyroidism or medication effects. A clear plan with tests every 6–12 months once stable keeps things simple and safe. If you’re unsure, a short chat with your clinician or pharmacist will often clear up the next steps fast.