Thyroid gland is a endocrine gland that produces hormones such as T3, T4 and calcitonin. You have subclinical hypothyroidism. The symptoms are fatigue, intolerance to cold, weight gain, odema, slurred speech. The medication is hormone replacement therapy in conventional medicine (synthetic hormone T4 to be taken daily empty stomach) and in homeopathy medicines like Bromium, Calcarea carb, Kali carb, Kali iod, Natrum mur, Thyroidinum, Pulsatilla, Sepia, etc.