He had lost none of his ability - it cannot suddenly disappear without physical cause.

No biological or physical cause could be found and the studies were abandoned.

Pain washed through him, but not from any physical cause.

If disease was not responsible, then perhaps the answer lay with a physical cause such as air pollution.

Even so, the testing focused first on the possible physical causes.

I wonder if there might not be some physical cause.

In many cases, however, no underlying physical cause can be identified.

Pain can be related to both physical and emotional causes.

In most cases, painful sexual acts have a physical cause at first.

These need to be addressed along with the physical causes of pain.