In Short
- Alopecia is the medical term for hair loss, and it covers several different conditions.
- The main types are pattern hair loss, alopecia areata, telogen effluvium and traction alopecia.
- The cause determines the type, and the type determines the treatment.
- Options include doctor-prescribed therapy, PRP, laser therapy and hair transplantation. Results vary.
Alopecia is the medical term for hair loss, and it is one of the most common conditions we see at Hair and Skin Science. It becomes more common with age: in an Australian study, pattern hair loss affected 73.5% of men and 57% of women aged 80 and over (Gan & Sinclair, 2005). Most hair loss is hereditary, though occasionally it is the first sign of an underlying medical problem. This guide covers what alopecia is, why hair falls out, the main types and what can help.
What is alopecia and how does hair loss happen?
Alopecia describes slower hair growth, thinning, excessive shedding, or a failure to replace hairs that are lost. Each follicle cycles through growth (anagen), transition (catagen) and rest (telogen), then the hair sheds and a new one grows. Most types disrupt this cycle: follicles shrink and make finer hairs, too many follicles rest at once, or the immune system halts growth (Pratt et al., 2017; Rebora, 2019).
Why is my hair falling out?
Hair loss can be gradual or sudden, patchy or diffuse, and more than one cause can be present at once.
- Genetics. Androgenetic alopecia runs in families, with more than 380 regions of the genome linked to it (Liu et al., 2025).
- Hormonal changes, including thyroid disease, pregnancy and menopause.
- Medications, including some blood thinners, cholesterol and heart rhythm medicines, and chemotherapy (Patel et al., 2013).
- Iron deficiency and other nutritional gaps (Almohanna et al., 2019).
- Physical or emotional shock, such as surgery, a high fever, rapid weight loss or major stress.
- Hair practices, including tight styles, chemical straightening and excessive heat.
Types of alopecia: pattern hair loss, alopecia areata and more
We identify the type from the pattern of hair loss, your history, a scalp examination and, where needed, blood tests.
Androgenetic alopecia (pattern hair loss)
This is the most common type. In genetically sensitive follicles, androgens shorten each growth cycle and the hair grows finer, until the follicle stops producing hair (Liu et al., 2025). Pattern baldness in men starts at the temples or crown. Women notice a widening part and thinning over the crown, often around menopause (Bhat et al., 2020). Pattern hair loss can progress over time, although progression and treatment response vary.
Alopecia areata
This autoimmune condition affects close to 2% of people at some point in their lives (Pratt et al., 2017). The immune system interrupts growth but leaves the follicle intact, so regrowth is possible. Look for smooth, round bald patches, sometimes after tingling or itching. In a small number of people it progresses to total scalp hair loss.
Telogen effluvium
Many follicles enter the resting phase together and shed three to four months after a trigger such as childbirth, a high fever or rapid weight loss (Rebora, 2019). It causes diffuse thinning, and the hair usually recovers once the trigger is corrected.
Traction alopecia
Tight ponytails, braids and extensions thin the hairline over time. It is reversible if caught early, but follicles can scar if the pulling continues (Billero & Miteva, 2018).
Alopecia treatment options
Treatment depends on the type and cause. Any underlying cause, such as iron deficiency, a thyroid problem or a medication, needs correcting first (Patel et al., 2013). Options, often combined, include:
- Medical therapy prescribed by a doctor
- PRP hair loss treatment
- Low-level laser therapy
- Hair transplantation where hair loss is more advanced
PRP concentrates platelets from a small sample of your own blood and injects them into the scalp. Meta-analyses of controlled trials in androgenetic alopecia have reported increased hair density compared with placebo (Gupta et al., 2019; Zhang et al., 2023). Any response builds over several months, and individual results vary.
When to see a doctor about hair loss
Persistent or unexplained hair loss can occasionally signal an underlying illness. If you are not taking a medication or having a treatment known to cause it, arrange blood tests and a scalp assessment with your doctor or a hair loss clinic. Healthdirect has general guidance. At Hair and Skin Science, PRP hair treatments are provided following a medical assessment and under the clinical supervision of a registered medical practitioner.
Key Takeaways
- The cause decides the type, and the type decides the treatment.
- Gradual thinning at the crown or temples can point to pattern hair loss, and round bald patches to alopecia areata.
- Heavy shedding months after illness, surgery or childbirth can point to telogen effluvium, which often recovers.
- Check iron, thyroid and medications before starting treatment. Results vary and are not guaranteed.
To find out what is behind your hair loss, book a free consultation. You can also read our alopecia hair loss page, or our pages on hair loss in men and women.
References
Almohanna HM, Ahmed AA, Tsatalis JP, Tosti A. The Role of Vitamins and Minerals in Hair Loss: A Review. Dermatol Ther (Heidelb). 2019;9(1):51-70. doi:10.1007/s13555-018-0278-6
Bhat YJ, Saqib NU, Latif I, Hassan I. Female Pattern Hair Loss: An Update. Indian Dermatol Online J. 2020;11(4):493-501. doi:10.4103/idoj.IDOJ_334_19
Billero V, Miteva M. Traction alopecia: the root of the problem. Clin Cosmet Investig Dermatol. 2018;11:149-159. doi:10.2147/CCID.S137296
Gan DC, Sinclair RD. Prevalence of male and female pattern hair loss in Maryborough. J Investig Dermatol Symp Proc. 2005;10(3):184-189. doi:10.1111/j.1087-0024.2005.10102.x
Gupta AK, Cole J, Deutsch DP, et al. Platelet-Rich Plasma as a Treatment for Androgenetic Alopecia. Dermatol Surg. 2019;45(10):1262-1273. doi:10.1097/DSS.0000000000001894
Liu Y, Tosti A, Wang ECE, et al. Androgenetic alopecia. Nat Rev Dis Primers. 2025;11:73. doi:10.1038/s41572-025-00656-9
Patel M, Harrison S, Sinclair R. Drugs and hair loss. Dermatol Clin. 2013;31(1):67-73.
Pratt CH, King LE Jr, Messenger AG, Christiano AM, Sundberg JP. Alopecia areata. Nat Rev Dis Primers. 2017;3:17011. doi:10.1038/nrdp.2017.11
Rebora A. Telogen effluvium: a comprehensive review. Clin Cosmet Investig Dermatol. 2019;12:583-590. doi:10.2147/CCID.S200471
Zhang X, Ji Y, Zhou M, et al. Platelet-Rich Plasma for Androgenetic Alopecia: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Cutan Med Surg. 2023;27(5):504-508. doi:10.1177/12034754231191461
This page is general information only and does not substitute individual medical advice. Individual results vary and outcomes are not guaranteed. Any medical procedure carries risks. Seek an assessment from a qualified practitioner to determine whether a treatment is right for you.
