Hi Vikashperiwal
Welcome to NeuroTalk

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An elevated ESR (erythrocyte sedimentation rate) is often a marker for inflammation or infection. It is non-specific, which means that it does not show whereabouts in the body the problem may be.
It might be an idea if you suggested to your mother that she sees an Ear Nose Throat specialist. An ENT specialist should be able to examine her and come up with suggestions about her throat.
All the best.