The different causes of diffuse hair loss
  Normally hairs that have completed their development phase fall out after the resting phase. It is considered normal to lose up to 100 hairs per day. There can be a number of reasons why more hairs are lost. Some of the causes of diffuse hair loss can be pregnancy, intake of certain medicines, and poor nutrition, for example.

Hair loss during pregnancy and after the birth
Women frequently lose more hair two to three months after the birth of a child (postpartum effluvium). This is because the oestrogen levels in the blood are very high during pregnancy. They drop sharply after the birth. More hairs therefore suddenly move from the growth stage to the resting stage - and two to three months later they fall out. As soon as the hormone levels normalise again, the hair loss ceases again by itself. Normally pregnancy-related diffuse hair loss lasts for six months after the birth.

Circular hair loss (alopecia areata)
In the case of circular hair loss (alopecia areata), people lose - usually only temporarily - hair in a defined, usually circular to oval area with a diameter of 2 to 2.5 centimetres. Alopecia areata can occur regardless of age or gender. The cause of alopecia areata is not known. Physicians recommend boosting the immune system and reducing stress factors. Healing is frequently spontaneous after a few months: as soon as immunity has recovered, the hairs grow again. 

Hair loss due to incorrect use of cosmetics products
Many cosmetics products contain synthetic substances that can trigger irritation or allergic reactions on the scalp. The incorrect use of such products can also disturb the balance of the scalp. The consequence: hair loss. These products are frequently shampoos, hair dyes or styling products that are not suitable for the user’s hair type.

Hair loss due to the intake of medicines
Some medicines - for instance blood coagulation preparations, antidepressants, antihypertensive medicine, birth control pills or high doses of vitamin A - can damage the hair roots particularly with long-term intake, and cause diffuse hair loss.

Hair loss due to imbalanced and unsatisfactory nutrition
Iron, zinc, sulphur and also B vitamins ensure that the hair remains healthy. Those who have an imbalanced or even deficient diet therefore frequently suffer from diffuse hair loss.