How do I know if my thyroid is working properly?

Detailed Explanation

Your thyroid gland is a butterfly-shaped organ in your neck that controls metabolism throughout your entire body. It affects your weight, energy, mood, heart rate, and more. Thyroid disorders are incredibly common - affecting about 20 million Americans, with up to 60% undiagnosed. Here's how to recognize if your thyroid isn't working properly:

• The thyroid produces hormones (T3 and T4) that control how fast every cell in your body works. Think of it as your body's thermostat:
• Too much hormone (hyperthyroidism) = everything speeds up
• Too little hormone (hypothyroidism) = everything slows down

*Affects 1-2% of the population; 80% caused by [Graves' disease](/condition/graves-disease)*

1. Weight and Metabolism - Unexplained weight loss (even eating more) - Increased appetite - Frequent bowel movements or diarrhea - Difficulty gaining weight

1. Energy and Sleep - Feeling wired, restless, can't sit still - [Insomnia](/condition/insomnia) or difficulty sleeping - Fatigue despite feeling "hyper" - Anxiety, nervousness, panic attacks

1. Heart and Circulation - Rapid heartbeat (100+ beats/min at rest) - Palpitations, pounding heart - High blood pressure - Atrial fibrillation risk

1. Temperature and Skin - Feeling hot when others are comfortable - Excessive sweating - Warm, moist skin - Flushing

1. Other Symptoms - Trembling hands (hold paper, notice shaking) - Muscle weakness (especially thighs) - Bulging eyes (Graves' ophthalmopathy) - Irregular menstrual periods - Fine, brittle hair - Thinning skin

*Affects 5% of population; 90% caused by Hashimoto's disease*

1. Weight and Metabolism - Weight gain despite eating less - Difficulty losing weight - Decreased appetite but still gaining - Constipation, slow digestion

1. Energy and Mood - Fatigue, exhaustion, no energy - [Depression](/condition/depression), low mood - Brain fog, difficulty concentrating - Memory problems - Sluggishness, feeling slow

1. Temperature and Skin - Feeling cold all the time - Cold hands and feet - Dry, rough, pale skin - Puffy face, especially around eyes - Swelling in legs

1. Hair, Nails, Voice - Hair loss (including outer eyebrows) - Dry, brittle hair - Brittle, ridged nails - Hoarse voice

1. Other Symptoms - Heavy or irregular menstrual periods - Muscle cramps and aches - Joint pain or stiffness - Slow heart rate - High cholesterol - Fertility problems

*Check symptoms you're experiencing:*

*If you checked 3+ symptoms in either category, consider getting tested.*

1. TSH (Thyroid Stimulating Hormone) - Most Important - First test ordered; screens for thyroid problems - Normal range: 0.4-4.0 mIU/L (varies by lab) - High TSH = underactive thyroid (thyroid struggling, brain sending more signals) - Low TSH = overactive thyroid (too much hormone, brain backs off)

1. Free T4 (Thyroxine) - Measures actual thyroid hormone level - Confirms TSH findings - Normal range: 0.8-1.8 ng/dL

1. Free T3 (Triiodothyronine) - Active form of thyroid hormone - Sometimes needed for complete picture - Important if T4 is normal but symptoms persist

1. Thyroid Antibodies - TPO antibodies: Detect Hashimoto's (autoimmune hypothyroidism) - TSI antibodies: Detect [Graves' disease](/condition/graves-disease) (autoimmune hyperthyroidism) - Thyroglobulin antibodies: Another marker for autoimmune thyroid disease

1. Thyroid Ultrasound - If nodules or goiter suspected - Checks thyroid structure

| TSH | T4 | Diagnosis | |-----|-----|-----------| | High | Low | Hypothyroidism | | Low | High | Hyperthyroidism | | High | Normal | Subclinical hypothyroidism | | Low | Normal | Subclinical hyperthyroidism | | Normal | Normal | Normal thyroid function |

1. Track your symptoms for 1-2 weeks (note when they occur, severity)
2. Schedule a doctor appointment - describe your specific symptoms
3. Request thyroid blood tests (TSH at minimum, ideally full panel)
4. Fast may not be required but check with your lab
5. Get results and discuss interpretation with your doctor
6. Follow up if subclinical - may need retesting in 6-12 weeks

• Very rapid heartbeat (150+) with other symptoms (thyroid storm risk)
• Severe fatigue with swelling, hoarse voice (myxedema risk)
• Eye bulging, vision changes, eye pain
• Large neck swelling
• Difficulty swallowing or breathing

• Both hyperthyroidism and hypothyroidism are very treatable:
• [Hypothyroidism](/condition/hypothyroidism): Daily thyroid hormone pill (levothyroxine) - feel better in weeks
• [Hyperthyroidism](/condition/graves-disease): Medications, radioactive iodine, or surgery - multiple effective options

With proper treatment, most people return to completely normal function and feel like themselves again.