Hi ,
you know hair loss can be natural (male pattern baldness) or other causes (deficiency of iron,calcium ,stress etc) .
hair loss other than male pattern baldness can be diagnosed with blood test like CBC,S.calcium ,your haemoglobin levels , thyroid hormones etc and this is not essentially balding . Once the cause is cured hair starts growing again .
male pattern baldness : its just caused by action of DHT . Though there are blood tests to determine your DHT levels , Testosterone etc this cannot be an indicator to balding . All depends on the sensitivity of your hair follicles to DHT .In other words its possible for low DHT levels and balding , Someimes even a high DHT level need not mean that person would become bald .So there cant be any SPECIFIC test to diagnose male pattern baldness.
male pattern baldness can be determined only based on your gene nature , hair loss nature , and history . male pattern baldness does not usually accompany by increased shedding.What u generally observe is the thinning/miniaturization of hair follicles . Terminal hairs converts to vellus type . So just check about strength of your hair instead of worrying about no of hairs u lose if you are concerned of male pattern baldness . In male pattern baldness the one may not even notice that he gets bald because of this thinning which is not accompanied by hair shedding . So the hairs which fall out as you comb , examine them - their strength ... if they are very fine lacking pigmentation , such hairs are signs of male pattern baldness . But 1-2 vellus hairs in every 12 hairs that u shed is not a problem .. An incresed fall of vellus type hairs are an indication of male pattern baldness .
However if u are taking propecia these vellus hair fall may indicate that in the next anagen phase they may be replaced by healthy hairs
However other hair loss (like stress triggered etc) are usually acompanied by increased shedding
TO CONCLUDE :
male pattern baldness cannot be diagnosed by blod test and there is also no increased shedding
Other hair falls can be diagnosed through blood test and it is mosty accompanied by rapid/increased shedding
NOTE : I AM TELLING THIS BASED ON MY OWN RESEARCH . I DONT HAVE ANY MEDICAL BACKGROUND . SO DONT TAKE IT A
S A FINAL WORD. THIS IS JUST A SUGGESTION