Postpartum thyroiditis is inflammation of the thyroid gland that can occur after you give birth. This condition often occurs in two phases. In the thyrotoxic phase, symptoms may include anxiety, insomnia, fatigue, weight loss, and irritability, which are often mistakenly attributed to stress. During the hypothyroid phase, you may experience fatigue, weight gain, constipation, dry skin, and depression. These symptoms can be mitigated with help from your doctor, and the majority of women regain normal thyroid function.