Severe hair fall after a cesarean delivery is very common and is usually due to postpartum hormonal changes (called telogen effluvium), and it can look worse if there is thyroid imbalance, even if you are already taking Eltroxin. The good news is that this type of hair loss is temporary in most women and gradually improves over a few months. While breastfeeding, you should focus on safe measures such as maintaining good nutrition with adequate protein, iron, calcium, and vitamins, staying well hydrated, and continuing your thyroid medicine regularly with periodic TSH checks to ensure the dose is correct. Gentle hair care (avoiding tight hairstyles, heat, and harsh chemicals) can also reduce breakage. If iron or vitamin D deficiency is present, your doctor may advise supplements that are safe in breastfeeding. Avoid self-starting strong hair treatments or hormonal medicines, and consult a doctor if hair loss is very severe beyond 6-9 months or associated with fatigue or other symptoms.