Do I have Telogen Effluvium? How long will it last? 19 year old male experiencing hair shedding for the past 7 months (Photo)

I suggest seeing a hair loss expert to evaluate and go over your condition and provide you information about your best treatment options. There are great non-invasive options like PRP/progesterone and/or hair transplantation if needed. See an expert. Best, Dr. Emer

TE lasting for seven months in a male patient with otherwise normal labs is not likely.   You are more likely noticing the early stages of androgenic alopecia which is by far more common.  It is important that you get a proper diagnosis and treatment plan from a specialist in hair loss. 

There are a few causes of shedding in men. Sure you can have telogen effluvium but it's not that common in men with normal blood test results.See a dermatologist to guide you. The most common cause of shedding in young men with normal blood tests is early androgenetic alopecia but please see a physician.

Your biggest enemy is the progressive thinning leading to a balding pattern that is not evident at this point in time and is most likely genetic balding not TE. A doctor can tell the difference with a pull test. The degree of thinning that you are experiencing would suggest that you should see a doctor who most likely will get Bulk Measurements of your hair to determine the degree of the thinning that you are presently having. If the diagnosis is early genetic hair loss (the most common cause of hair loss in young men), then the best treatment would be the drug finasteride which is highly effective in men of your age and may not only stop the hair loss but possibly reverse it. If you are developing a more advanced balding pattern the HAIRCHECK test will determine the Bulk Measurements of your hair and put a number on that hair loss (a metric) and this will show, over a one-year time frame, how effective the treatment will be. Once you know this information, then you and your doctor need to develop a MASTER PLAN which will define what you need to do over the years to come.