Health

ma ei tunne ennast hästi - I'm not feeling well
mul on paha olla - I'm not feeling well

ma vajan arsti - I need a doctor

mul pea valutab - I have a headache
mul on peavalu - I have a headache

kas sul on valuvaigistit? - do you have any painkillers? (familiar)
kas teil on valuvaigistit? - do you have any painkillers? (polite)