Hello. Thank you for writing to us at healthcaremagic Sudden/ acute hair fall is known as Telogen Effluvium. Telogen is the resting phase of hair growth cycle and once hair enters Telogen, it is shed over the next few days. There may be various causes for transition to telogen phase. Most of these causes are identifiable in the history of the patient, in the preceding 3-4 months before onset of Telogen. Telogen usually begins 2-3 months after a stressful event/ triggering event. This stressful event can be a preceding medical illness like e.g dengue, malaria, jaundice etc; a major surgery is also usually followed by telogen that begins 3-4 months after the stressful event. Other common causes are deficient Iron stores; Weight loss/ dieting; post pregnancy/ post partum, certain drugs etc. These causes if identified can be addressed appropriately. Telogen usually lasts 3-6 months and hair loss recovers if the inciting factor is identified and removed. I usually ask my patients to take a good healthy diet rich in nutrients, vitamins and minerals. An Iron supplement may be added over the next 4-6 months as Iron stores are a common cause of hair fall in females. A Biotin supplement is also beneficial for hair. Biotin helps in recovery and is essential in the synthesis of protein that builds hair. I suggest you to visit a dermatologist for a confirmatory diagnosis as well as appropriate treatment. Topical minoxidil solution/ liquid may also be started by your treating dermatologist and is quite useful in cutting short telogen effluvium. Regards