There are various types of hair loss. The type of the hair loss will decide what the appropriate remedy there is, if there is any.
This type of hair loss make round bald patches occur at the front and going across the top of the head. This type of hair loss is considered to be mostly genetic. So if your parents had bald issues then it is likely that you will also. This is the most common form of baldness, and is suffered mostly by men. there are various different products out there which can deal with this. There are FDA approved products, and also some DHT blockers such as Nettle Root which may help also. Generally though which ever treatment is chosen, realistically results are not instant and can take 6 months or more to show.
This is where thinning and sports of bald are in patches. It mostly occurs in women as it can be caused by the blood loss which occurs during the menstrual cycle. It is this in conjunction with a lack of iron due to the blood loss which can cause the loss of hair. Generally this will not happen over night but rather over a longer period. Generally the damage done in this case is reversible with Iron added to the diet. Red meat is the easiest way to get iron levels up alternatively for vegetarians green leafy vegetables work well.
This type of hairloss is normally temporary and is a direct after effect of pregnancy. This is because during pregnancy women stop shedding hair, and after birth the mechanism goes back to normal. There is also a hormone called DHEA which can cause hair loss in women
Alopecia areata is where patches of hair loss occur on the scalp. These patches are not confined to the scalp, they can potentially appear anywhere on the body. This occurs due to the immune system attacking the hair follicles.