【Trouble】 ,  【distress】 ,  【ail】  can all mean to cause to be uneasy or upset.

【Trouble】 suggests loss of tranquillity or serenity and implies disturbance of any sort that interferes with efficiency, convenience, comfort, health of body, or peace of mind.

【Distress】  implies subjection to strain or pressure that causes such reactions as tension, pain, worry, or grief; thus, a cough distresses when it is tight and persistent; the formation of gas in the stomach distresses by its pressing bloating effect; a person is distressed in mind when anxiety distracts or crushes him; a person is financially distressed when he is in circumstances so straitened that he cannot pay his debts or satisfy his needs.

【Ail】  implies that something has gone wrong or is the matter; in contrast to  【trouble】  and  【distress】  it is used only in respect to unspecified causes; thus, a cough may be said to  【trouble】  or to  【distress】  a person but not to  【ail】  him; one can be troubled or distressed but not ailed by something disturbing.