Hair and Scalp Structure, Growth, and Disorders for the Cosmetology Exam

How the NIC theory exam tests hair and scalp knowledge

Hair and scalp appear in two domains of the NIC National Cosmetology Theory Examination bulletin (effective July 1, 2022, revised January 1, 2026). Scientific Concepts, worth 35%, asks you to identify the function and structure of the hair and scalp and to recognize signs and symptoms of conditions, disorders, and diseases related to them. Hair Care and Services, worth 45%, asks you to evaluate the condition of a client's hair and scalp and to recognize conditions that would prohibit a service.

The first set is recall: names, layers, phases. The second set is judgment: what you see on a client, and what you do about it. Most of the risk on this topic sits in the second set, because a wrong call can spread an infection or injure a client.

That bulletin is still the one NIC posts as of October 28, 2026, and NIC has announced no replacement, so a 2027 candidate in a state that uses the NIC theory exam studies the same outline. The bulletin itself tells you to check your exam provider's site or nictesting.org for the most current version before you test.

The hair shaft and follicle in plain words

MedlinePlus, the National Library of Medicine's consumer health site, describes hair follicles as the structures in the skin that make and grow hair, and says hair color comes from melanin that the follicles produce. Hair itself is made of protein strands. A 2015 review in the International Journal of Trichology divides the shaft into three regions:

Your textbook names the smaller parts of the follicle and root. Learn them there, from the edition your bulletin lists, and connect each part to a service: where the hair grows from, where pigment is made, and which part a chemical can reach.

The hair growth cycle and shedding

Each follicle cycles through three main phases. Cleveland Clinic, a nonprofit academic medical center, describes them as anagen, the growth phase; catagen, a short transition; and telogen, a resting phase that ends when the hair sheds and the cycle starts again. Most follicles are growing at any moment. Cleveland Clinic puts that share at about 80% to 90%, and published figures for the other two phases vary by source, so learn the order and the meaning rather than one exact percentage. MedlinePlus gives a single hair a normal life of 2 to 7 years before it falls out and is replaced.

Shedding matters on the exam because clients describe it during consultation. Cleveland Clinic says most healthy people lose up to about 100 hairs a day. In telogen effluvium, a temporary type of hair loss, a stressor such as a high fever, childbirth, major surgery, or a severe infection pushes growing hairs into the resting phase early, and the extra shedding tends to show up two to three months later. Cleveland Clinic adds that the scalp should look healthy, with no rash, itching, or flaking.

A worked consultation (fictional client). Dana says her hair has been coming out in the shower for three weeks. She had surgery about three months ago, and her scalp looks healthy, with no redness, scaling, or bald patches. The timing matches hairs that entered the resting phase after a stressor and are now shedding. The cosmetologist's job is not to name the condition. It is to handle the hair gently, avoid promising that a product will stop the shedding, and suggest that Dana mention it to her physician. Nothing on her scalp prohibits a gentle service.

Once you can explain why the timing points to the resting phase, drill hair growth phases with the flashcards planned for full cosmetology prep. Phase names and their order are the kind of recall that should come without effort by exam day.

Scalp conditions: recognize, then decide

The table below sorts signs you may see before a service. The middle column says what public health sources describe, not a diagnosis you would give a client. The right column is the exam-safe decision. Your state's rules and your school's procedures govern the details.

Two rows look alike at first glance. Both ringworm of the scalp and alopecia areata can leave patches with short broken hairs, but MedlinePlus describes ringworm patches as scaly and often inflamed, while NIAMS says alopecia areata patches usually show no rash, redness, or scarring. You don't need to tell them apart for the client. You need to notice that scaling and inflammation point toward something possibly contagious, and stop.

Two habits keep the decision column safe. Describe what you see, not what you think it is: "I see some areas on your scalp that a doctor should look at before we do any services" works, while "you have ringworm" is a diagnosis. And do not recommend or sell a product as a treatment. MedlinePlus notes that ringworm of the scalp is treated with medicine a health care provider prescribes, and that medicated shampoo alone does not get rid of it. When those habits feel automatic, practice by NIC domain in the full cosmetology prep planned for launch, where scalp findings sit in both Scientific Concepts and Hair Care and Services.

A worked decline (fictional client). Before a haircut, you find two round, scaly patches on Theo's crown with short broken hairs at their centers. The signs match a contagious fungal infection. Stop before cutting, tell Theo privately and kindly that the scalp should be seen by a doctor first, and reschedule. Then clean and disinfect the comb, shears, cape, and station that touched him, following your disinfectant's label and your state's rules. MedlinePlus's home-care steps, such as soaking household combs in diluted bleach, are written for families at home. They do not replace the salon procedure your state requires.

With that sequence clear, try the contagious-scalp-condition question in the free cosmetology practice set. It turns the same signs into a four-option choice and explains every option.

Scope: cosmetologists recognize and refer

The NIC outline's verbs set the limit. You "recognize signs and symptoms" and "recognize conditions that would prohibit service." Nothing in the outline asks you to diagnose or treat. The California board's current PSI outline, a different exam, spells out the same boundary as a consultation task: recommending that the client seek a medical opinion. On a multiple-choice item, answers that name a disease to the client, suggest a medication, or continue the service "carefully" around a possibly contagious condition are the distractors.

The consultation and patch test guide covers the full intake, including client records. Shampoo choice and scalp massage for healthy scalps are in the shampoo and draping guide, and the cleaning steps after a contagious condition are in the cleaning, disinfection, and sterilization guide.

Once the table and the scope rule hold up from memory, test them under exam timing. You can rehearse with the 110-question timed mock exam planned for launch, which follows NIC's 90-minute format.