I am losing eyelashes. around 4-5 a day. is that normal?

Often temporary: Some degree of eyelash loss or turnover is normal and can be associated with the lash growth cycle. If an excessive number are being lost, make sure you're not a) rubbing the eyes b) applying any lotion or make-up you may be sensitive to and c) have a build up of oils at the lash bases called blepharitis or meibomian dysfunction. For the latter apply warm compress and light baby shampoo at night.

Probably not: Some eyelash loss over time is normal but it sounds like you are losing more than the expected normal amount. You need to avoid rubbing your lids, no pulling your lashes, eat a balanced diet, have your doctor check your thyroid levels, and see an eye doctor to rule out other disease that may be causing this issue.