What's the matter with him?
He has a stomachache.
This is one of the causes of stomachache.
Eat unhygienic food
What's the matter with him?
He has A TOOTHACHE.
What's the matter with her?
She has SORE EYES.
This is one of the causes of backache.
Watch TV for a long time
This is one of the causes of toothache.
Eat too much sweets
This is one of the causes of backache.
Carry heavy objects
What's the matter with him?
He has A BACKACHE.
What's the matter with her?
She has A FEVER./ She a has temperature.
This is one of the causes of sore throat.
Eat too much ice cream