Why do you lose your period when underweight?

Hormonal Imbalances: Being underweight can disrupt the delicate balance of hormones in the body, especially the reproductive hormones estrogen and progesterone. These hormones play a crucial role in regulating the menstrual cycle. Low levels of body fat can signal to the brain to reduce the production of these hormones, leading to skipped or absent menstrual periods.

Low Body Fat: A certain amount of body fat is necessary for the proper functioning of the reproductive system. When you're underweight, your body fat stores may be depleted, which can affect the production of hormones involved in the menstrual cycle.

Hypothalamic Dysfunction: The hypothalamus, a small region in the brain, is involved in regulating body functions like appetite, sleep, and reproductive functions. Being underweight can disrupt the hypothalamus's normal functioning, leading to disruptions in the menstrual cycle, such as irregular periods or amenorrhea (absence of menstruation).

Nutritional Deficiencies: Severe undernutrition can result in a deficiency in essential nutrients, such as iron, vitamins B and C, and protein, which are all important for reproductive health and the proper functioning of the menstrual cycle.

Increased Stress and Cortisol Levels: Chronic stress and elevated cortisol levels can affect the hypothalamus-pituitary-ovarian axis, the pathway that controls the menstrual cycle. Stress can also divert resources away from reproductive processes and toward survival responses, leading to hormonal imbalances and irregular menstrual cycles.

Weight Loss: Rapid weight loss or following restrictive diets can put stress on the body and disrupt hormonal balance, potentially leading to the loss of menstrual periods.

Exercise: Excessive exercise may contribute to amenorrhea in some women, particularly those with low body fat. Strenuous physical activity can further reduce body fat stores and may disrupt hormonal balance.

Underlying Medical Conditions: In some cases, amenorrhea associated with being underweight may indicate an underlying medical condition, such as thyroid disorders, pituitary gland issues, or reproductive disorders.

If you're underweight and concerned about your menstrual irregularities, it's important to consult with a healthcare professional to rule out any underlying causes and receive appropriate guidance. Proper nutrition, weight gain (if recommended by a healthcare provider), stress management, and addressing nutritional deficiencies can help restore hormonal balance and menstrual regularity.