TSH & Thyroid Guide
What TSH levels mean, high vs low TSH, hypothyroidism vs hyperthyroidism, and how thyroid lab tests help diagnose and monitor thyroid conditions.
What Is TSH in a Blood Test?
Understand TSH (thyroid-stimulating hormone) in your blood test: normal range, what high TSH and low TSH levels mean, hypothyroidism and hyp…
What Does High TSH Mean?
What a high TSH blood test result means: causes of elevated TSH including Hashimoto's thyroiditis, when levels are dangerously high, and wha…
What Does the Thyroid Do?
Learn what the thyroid gland does in the body: how it regulates metabolism, heart rate, body temperature, brain development and cholesterol,…
What Is Considered a Dangerously High TSH Level?
TSH above 10 mIU/L is overt hypothyroidism; above 50 is dangerously high. Learn the thresholds and symptoms of severe hypothyroidism.…
What Does Low TSH Mean?
Low TSH (below 0.4) usually means hyperthyroidism. Causes include Graves' disease, toxic nodules, thyroiditis, and over-replacement with thy…
What Is Hypothyroidism?
Hypothyroidism (underactive thyroid) explained: causes including Hashimoto's, symptoms, diagnosis, and treatment with levothyroxine.…
What Is Hyperthyroidism?
Hyperthyroidism (overactive thyroid) explained: causes (Graves' disease, toxic nodules), symptoms (rapid heart rate, weight loss, anxiety), …
What Is Hashimoto's Thyroiditis?
Hashimoto's explained: the autoimmune cause of hypothyroidism, anti-TPO antibodies, symptoms, diagnosis, and treatment.…
Can Hypothyroidism Be Cured?
Hashimoto's is lifelong, but drug-induced and subclinical cases may reverse. Learn which types are permanent and which are temporary.…
How to Treat Hypothyroidism
Hypothyroidism treatment: levothyroxine dosing, TSH monitoring, alternatives (Armour, Cytomel), and lifestyle factors.…
What Causes Hypothyroidism?
Causes: Hashimoto's (most common), thyroid surgery, radiation, medications (lithium, amiodarone), iodine deficiency, and congenital.…
What Are Normal TSH Levels?
Normal TSH: adults 0.4-4.0 mIU/L, pregnancy ranges, and why some clinicians prefer 0.5-2.5 as optimal.…
What Is a Low TSH Level in a Woman?
Low TSH in women: causes specific to women include pregnancy, postpartum thyroiditis, and PCOS. When does low TSH need treatment?…
What Does Your Thyroid Do?
Your thyroid regulates metabolism, heart rate, body temperature, brain development, and cholesterol through T3 and T4 hormones. Learn how it…
What Are Thyroid Stimulating Hormones?
TSH (thyroid-stimulating hormone) explained: how the pituitary regulates the thyroid, normal ranges, and what abnormal TSH levels indicate a…
What Are the Symptoms of Thyroid Problems?
Thyroid symptoms: underactive (fatigue, weight gain, cold intolerance, dry skin, constipation) vs overactive (anxiety, weight loss, rapid he…
What Is the Thyroid Gland?
The thyroid gland explained: a butterfly-shaped organ in the neck producing T3 and T4 hormones that regulate metabolism, heart rate, and bod…
How to Check Your Thyroid at Home
Self-check your thyroid: look for neck swelling, feel for nodules while swallowing, and watch for symptoms. But blood tests (TSH) are the on…
What Is Thyroid Storm?
Thyroid storm is a life-threatening hyperthyroid crisis: fever above 104°F, extreme rapid heart rate, confusion, delirium. Requires ICU trea…
What Is Myxedema Coma?
Myxedema coma is a life-threatening hypothyroid crisis: hypothermia, extreme slow heart rate, confusion, unconsciousness. Requires emergency…
What Is a Thyroid Nodule?
Thyroid nodules are lumps in the thyroid gland. 50% of people have them by age 60. 90–95% are benign. Evaluation includes ultrasound and pos…
What Is a Goiter?
A goiter is an enlarged thyroid gland. Causes include iodine deficiency, Hashimoto's, Graves' disease, and nodules. Treatment depends on the…
What Is Graves' Disease?
Graves' disease is an autoimmune condition causing hyperthyroidism. TSI antibodies stimulate the thyroid. Symptoms include bulging eyes, rap…
What Is Thyroid Eye Disease?
Thyroid eye disease (Graves' ophthalmopathy): bulging eyes, double vision, eye irritation. Caused by autoimmune inflammation of eye muscles.…
What Is Postpartum Thyroiditis?
Postpartum thyroiditis affects 5-10% of women after childbirth. Starts with hyperthyroid phase (1-4 months), then hypothyroid phase (4-8 mon…
What Is a Thyroid Uptake Scan?
A thyroid uptake scan uses radioactive iodine to image the thyroid. High uptake = Graves' disease. No uptake = thyroiditis. Focal uptake = t…
What Is a Thyroid Antibody Test?
Thyroid antibody tests (anti-TPO, TSI, anti-thyroglobulin) diagnose autoimmune thyroid disease: Hashimoto's (anti-TPO) and Graves' (TSI).…
How to Read a Thyroid Blood Test
Reading thyroid results: TSH (pituitary signal), free T4 (thyroid output), free T3 (active hormone). High TSH + low T4 = hypothyroidism. Low…