My thumb nails always crack on the sides, even after I cut it down. Why is it doing this?

I am a typist and I use my thumbs a lot, but I don't understand why my nails are so weak on the sides that they keep cracking. Any suggestions???My thumb nails always crack on the sides, even after I cut it down. Why is it doing this?
Allergies or harsh soap; getting the nail too dried out, nutritional deficiencies or a nail file that is not fine enough.My thumb nails always crack on the sides, even after I cut it down. Why is it doing this?
it can be caused by a fungus or a nail bed infection. have it checked out by a dr. :)
Ive been using almond oil on my fingers and thumbs to stop them cracking. It strenghens the nails, also use a nail strenghtner

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