Detailed answer

Dark circles and under-eye bags can be caused by various medical conditions. Allergies, such as hay fever, can cause your body to release histamines, leading to blood vessels swelling and darkening the skin around the eyes. Anemia, which is a deficiency in red blood cells or hemoglobin, can cause a lack of oxygen supply to the tissues, resulting in dark circles. Dehydration can make the skin under the eyes appear sunken and shadowed. Thyroid disorders, such as hypothyroidism or hyperthyroidism, can disrupt the normal functioning of the thyroid gland, causing fluid retention and puffiness around the eyes. Additionally, sleep disorders and chronic fatigue can also contribute to the appearance of dark circles and under-eye bags. It's important to consult a healthcare professional to determine the underlying cause and receive appropriate treatment for these conditions.