Yes, you would be able to recover them back.
The hair loss can be due to;
a) Presence of systemic disease like thyroid, iron deficiency, systemic lupus erythematosus, dermatomyositis.
b) Recent psychologic or physical stress
c) Medication or chemical exposure
So you doctor need to do the blood work for above systemic diseases and also do the following tests;
1) Hair Pluck -Trichogram
2) Hair growth window
3) Hair pull test
4) Hair shaft examination (Clip test)
Severe emotional and physical traumas have been documented to cause diffuse hair loss. Hair loss has been reported to occur 2 weeks after severe psychologic or physical trauma. Chronic telogen effluvium (CTE) refers to a diffuse hair loss all over the scalp and persists for more than 8 months. People present with hair loss with increased shedding and thinning of abrupt onset and fluctuating course. There is diffuse thinning all over the scalp, frequently accompanied by bitemporal (both the sides of scalp) recession. The causes can be;
1) Crash diet (inadequate proteins)
2) Drugs; coumadin propranolol, heparin, vitamin A
3) Hypothyroidism and hyperthyroidisms
4) Severe illness
5) Physical stress like surgery
6) Psychological stress.
It is privilege assisting you.