hair meme
On average you lose 50 to 100 hairs a day. This is considered normal hair loss. If you go a few days between shampooing you may even notice more hair falling out when brushing, and this is normal as well. If you feel you are experiencing excessive shedding, here are some possibilities as to why.
Physical stress
Any kind of physical trauma can cause hair loss. This includes surgery, a car accident, or a severe illness, pregnancy, even the flu. These incidents can trigger a type of hair loss called telogen effluvium. Hair has a programmed life cycle: a growth phase, rest phase and shedding phase. When you have a very stressful event happen your body can trigger the shedding phase to last longer. Hair loss often becomes noticeable three-to-six months after the trauma. 
What to do: The good news is that hair will start growing back as your body recovers.
Lack of protein-
If your not getting enough protein in your diet your body may halt hair growth to ration the protein.
What to do- Eat more protein! Great sources of protein include, fish dairy and eggs. Vegan options include quinoa, nuts, beans, tofu and many more.
Hereditary Hair loss 
this is also know as androgenetic alopecia and is a common cause of hair loss in men and women. 
Men can experience male pattern baldness which affects 2 out of three men by the age of 60.  This type of hair loss, caused by a combo of genes and male sex hormones, usually follows a classic pattern in which the hair recedes at the temples, leaving an M-shaped hairline. 
Female pattern hair loss is basically the female version of male pattern baldness. Unlike men, women don’t tend to have a receding hairline, instead their part may widen and they may have noticeable thinning of hair. 
What to do: There are topical creams like minoxidil (Rogaine) and oral medications such as finasteride (Propecia) that can halt hair loss or even cause some to grow; surgery to transplant or graft hair is also an option. Products such as Nioxin and Bosley are also known to slow down the process of hair loss. Hair pieces and wigs are great solutions for easy, no fuss hair styles. Getting a hair cut can also conceal noticeable thinning. Short hair styles tend to be more flattering for fine or thinning hair. Cutting off some length gives the illusion of thicker strands
 
Hormones
Hormonal changes are a very common reason for hair loss. More so in women. Hormonal changes range from pregnancy, starting or ending a new birth control, and menopause. Underlying health conditions such has hyperthyroidism can cause an unbalance of hormones as well. Speak to your doctor if you believe you have an underlying health condition.
What to do: Wait! Hair will grow back when your hormones are leveled out. Until then, volumizing and bodyfying hair products are great for giving your hair extra fullness for thicker looking hair.
 
Medication
Starting or stopping a new medication can promote hair loss.
What to do: speak to your doctor about your hair loss. Ask about any alternatives available.
 
Breakage
Breakage is caused by hair damage and is different from hair loss. With hair loss, the hair bulb falls out from the hair follicle. With Hair breakage, hair often breaks in the middle or ends of the hair were it has been weakened. This can happen when the hair is chemically over processed or there is excessive heat being used on the hair.
What to do- Leave-in treatments are great for moisturizing and protecting the hair. Use a thermal protector when using flat or curling irons to protect it from the heat. Leave the hair color to the professionals. Hair is often over processed unknowingly by doing hair at home. Consult your hairstylist for more hair repair options.