The emerging labor shortage is viewed as a sign of economic overheating.

Thunder indicates that a storm is near.

Like most diseases, it has its own symptoms.

Sudden decrease in appetite is sometimes a sign of illness.

We are always conscious of the signs.

But there had been no indications Gorbachev was having any sort of health problems, and it is not exactly clear what's happened to him now.

All the signs are that she is getting better.

There's no sign of infection.

This is a bad sign.

Signs of social unrest are mounting.

That's a bad sign.

Fever indicates sickness.