I think a lot of us confuse having fine hair with thin hair. My hair is not thin, as I have a lot of hairs on my head; but, it is fine because the strands are thin. Those of us who have fine hair face some of the same challenges, though.
The term “fine” refers to the actual diameter of the shaft of an individual hair strand. The term “thin” is used to reference the number of hairs per square inch dispersed amongst the entire head and is also used to describe the density of an individual’s hair. Regardless of the term that is used to describe one’s tresses, the same problems often occur with each hair type.
Hair texture is often described in terms of fine, medium, or coarse, which refers to the diameter of the strands. Hair density is usually described in terms of thin, medium, or thick, which refers to the compactness or concentration of the hair. The texture a person is born with is often determined by their genetic makeup. On the other hand, thin hair can be caused by a wide variety of factors, like an individual’s diet, their age, illnesses, etc. It is best to consult your physician in order to determine the underlying cause, usually the cause can often be successfully treated and the effects reversed.
In both cases - fine hair and thin, low-density, hair - you can have similar problems with the way the hair looks. Both situations result in flatter hairstyles and in both cases, the hair is more susceptible to damage from styling and chemical processes. There are ways to protect against this damage, and there are many products available today to deal with both hair traits - fine hair and low density - to give you thicker-looking, fuller hair.
For my fine hair, I also experience tangles and sensitivity to thick products and heavy oils. I’ve learned that a little goes a long way with most products. I also have to shampoo or co-wash my hair often to get rid of product build-up. Protein is key. Clarifying is key. I haven’t had much luck with “thickening” hair products. I find that they either make my hair more tangled or stiff.
Source 1, Source 2