An underactive thyroid gland (hypothyroidism) is where your thyroid gland doesn’t produce enough hormones. Treatment options include:
The easiest and most effective treatment is simply taking a thyroid hormone pill (Levothyroxine) once a day, preferably in the morning. This medication is a pure synthetic form of T4 which is made in a laboratory to be an exact replacement for the T4 that the human thyroid gland normally secretes. It comes in multiple strengths, which means that an appropriate dosage can almost always be found for each patient. The dosage should be re-evaluated and possibly adjusted monthly until the proper level is established. The dose should then be re-evaluated at least annually.
Some people start to feel better soon after beginning treatment, while others don’t notice an improvement in their symptoms for several months. An underactive thyroid is a lifelong condition, so you’ll usually need to take levothyroxine for the rest of your life.
Although many foods can improve thyroid function, changes to your diet are unlikely to replace the need for prescription medication.
Nuts and seeds rich in magnesium and selenium, including Brazil nuts and sunflower seeds, can be beneficial to your thyroid health.
Dietary supplements, like iron and calcium pills, and eating a high-fiber diet can reduce the absorption of certain thyroid medicines. In general, avoid eating soy and soy-based foods, kale, broccoli, cauliflower, and cabbage as these foods can inhibit thyroid function, especially when eaten in raw form.
Hypothyroidism can trigger muscle and joint pain and can leave you feeling fatigued and depressed. A regular exercise routine can reduce many of these symptoms.
References:
http://www.healthline.com/health/hypothyroidism/treatment-options#2
http://www.endocrineweb.com/conditions/thyroid/hypothyroidism-too-little-thyroid-hormone-0