All of my life I have fought weight gain, intolerance to cold, brittle nails, and hair loss, and absence or infrequent menstrual periods. My thyroid (TSH) tests all come back normal. Could I still have hypothyroidism even though the test says my thyroid is normal? I m experiencing more weight gain now that I m in my 60 s even though I walk 45 minutes 4-5 days a week, have cut my food intake in half and lead an active lifestyle.