What are early warning signs of thyroid problems? Early warning signs of thyroid problems include fatigue, unexplained weight changes, difficulty concentrating, changes in skin and hair texture, muscle weakness, and irregular menstrual cycles. Swelling in the neck, known as a goiter, can also be a symptom. Mood changes, such as depression or anxiety, may occur. If you experience these symptoms, it's essential to consult a healthcare professional for a thorough evaluation and proper diagnosis of any potential thyroid issues.