Is there a way to test hair follicles to see if they are active or dead?

There is no way to "test" if your hair follicles are active. One obvious way to tell is if you see hairs grow.  If you notice no hair growth for 6 to 12 months then it probably is a "dead" follicle.Hair loss due to stress will be diffuse.  Hair loss due to DHT from genetic male pattern balding will have a "pattern".

I appreciate your question.Hair follicles can be seen as well as the hairs around them. Depending on you age, their location and your family history it may be genetic. Stress does play a role but will may not be in the normal male pattern baldness patterns.The best way to assess and give true advice would be an in-person exam.Please see a board-certified plastic surgeon that specializes in aesthetic and restorative plastic surgery.best of luck!Dr Schwartz

If there are hair follicles they are active, if there are none they are dead. thats the bottom line.  If they are there but thin and not as dark they may be going through a thinning cycle and need treatment.  The fate of your hair loss is genetically determined unless its stress or autoimmune or traction induced.  I suggest a formal evaluation.  Best, Dr. Emer.

The number one first step I recommend is a comprehensive consultation
with a hair regrowth specialist who will perform lab tests to determine
the underlying cause of your thinning.  Without labs, no-one can really
know what your true cause is and any treatment will be temporary at
best.
From here, you can receive the best treatment for your case.
Good luck on your search

Hair follicles are only considered 'dead' if they have been destroyed by a primary (dermatological) or secondary (eg burns or trauma leaving scars) scarring alopecia. Otherwise, even if they are not producing hairs they may still be viable. Current research is aimed at re-awakening them. The medication available now such as minoxidil and finasteride has limited and unpredictable effect in restoring miniaturised hairs to terminal ones and are unlikely to get a new hair to grow if the follicle has shut down compmetely.