Genetics: A genetic disease called androgenic alopecia or pattern baldness is the leading cause today. It can contact both masculine and females.

Hormonal Changes: Silent ailments such as pregnancy, childbirth, menopause, and thyroid-related diseases result in hair loss.

Medical Conditions: Some diseases that affect hair are alopecia areata, some scalp infections and diseases such as lupus will lead to thinning of hair.

Medications: Certain drugs like Cancer treatments, arthritis, anti-depressants, cardiovascular medications, and high blood pressure medication, lead to hairline thinning as one of their effects.

Nutritional Deficiencies: Deficiency in certain nutrients dangerous for body tissues including vitamins and minerals for example iron, vitamin D and protein leads to thinning hair.

Medications: Isotretinoin used for treating acne, cancer drugs, drugs for rheumatoid arthritis, antidepressants, anti-heart failure drugs, and anti-hypertensive may lead to hair thinning.

Nutritional Deficiencies: Deficiencies can be caused by the absence of crucial macronutrients, micronutrients like vitamins, and Iron, Vitamin D, and protein all contribute to thinning hair.

Stress: Stress which could be physical or even emotional in origin leads to what is known as telogen effluvium, where hair is shed easily because it is in the resting phase.

Hairstyling Practices: Hair becomes thin when one uses chemicals on hair, styles hair frequently and dyes or perm the hair often thus applying excessive heat on hair.

Aging: Hormonal changes that occur with increasing age or any related conditions result in a decreased hair growth rate and hair tends to be thin and less shiny.

Environmental Factors: Hair health does depend on the quality of the environment people live in since pollutants and toxins in the environment do harm hair in the long run.

Poor Scalp Health: There are various treatments for hair troubles such as dandruff, psoriasis, or seborrheic dermatitides which cause thinning of hair.