Most hair loss falls into one of three broad categories — hormonal, nutritional, or autoimmune — each with its own pattern and lab markers. You can't diagnose yourself from a blog post, but knowing which category your symptoms sound like helps you ask a provider the right questions and request the right bloodwork, instead of starting with a supplement aisle and guesswork.
Hair loss is a symptom, not a diagnosis. The same visible result — more hair in the shower drain, a widening part — can come from genetics, a hormone shift, a nutrient shortfall, an autoimmune attack on the follicle, or some combination of these. Reaching for a shampoo or a biotin gummy without knowing which is happening is like taking cough medicine without knowing if you have allergies or a cold. The categories below are a starting point for the questions to bring to a provider, not a self-diagnosis tool.
Hair follicles are metabolically demanding, so the body deprioritizes them when nutrients run short — meaning a real deficiency can show up as shedding before other symptoms do. The most consistently linked nutrients are iron/ferritin, vitamin D, zinc, and protein. Biotin deserves a note: it's marketed aggressively for hair loss, but true biotin deficiency is uncommon in people eating a normal diet. The American Academy of Dermatology has cautioned that biotin supplementation isn't well-supported for hair growth in people who aren't actually deficient, and unnecessary high-dose biotin can even skew certain lab results. Nutritional hair loss also shows up after crash dieting or rapid weight loss, which can trigger the same diffuse shedding pattern described below.
Autoimmune hair loss tends to look more patchy or sudden than hormonal or nutritional shedding, but that's a generalization — a scalp exam is what actually sorts it out.
Thyroid imbalance, postpartum hormone shifts, and crash dieting can all produce the same effect: a wave of hair shifting into its shedding phase a few months after the trigger. This pattern is called telogen effluvium — a temporary, whole-scalp shedding response to a physical or hormonal stressor rather than a diagnosis on its own. According to the Cleveland Clinic, it's usually triggered by things like childbirth, illness, major surgery, extreme stress, rapid weight loss, or a change in thyroid hormone levels, and hair typically grows back once the underlying trigger resolves. It's a reminder that these three categories often overlap or feed into each other rather than staying in separate boxes.
Yes, and this matters more than picking a single category. Someone with Hashimoto's thyroiditis (autoimmune) may also have malabsorption that creates an iron or vitamin D deficiency (nutritional), while the thyroid dysfunction itself independently pushes hair into a shedding phase (hormonal). Someone with PCOS may have androgen-driven thinning plus a nutrient shortfall from a narrowed diet. This overlap is exactly why a single product or supplement so often falls short — the visible symptom looks the same, but the combination of drivers underneath is different for every person.
A real workup generally includes a detailed history (timeline, recent illness, diet changes, medications, family history), a scalp exam (diffuse vs. patchy shedding, miniaturization, inflammation), and bloodwork — typically a thyroid panel, ferritin/iron studies, and vitamin D, with androgen levels checked when PCOS or androgenetic alopecia is suspected. Sometimes a scalp biopsy is needed when the pattern suggests a scarring or autoimmune process. The pattern and timeline offer real clues, but labs and an exam are what confirm which category — or combination — is actually driving things.
At Three D Wellness in Roswell, GA, Dr. Sonza Curtis — patients' "gut doctor" — along with holistic health coach Heidi and weight-loss and nutrition coach Sharon Muse, use advanced lab testing to look across all three categories at once instead of guessing at one. That means checking thyroid function, iron and nutrient status, inflammatory markers, and hormone levels together, because a root-cause approach only works if it's actually looking for the root cause rather than treating the scalp in isolation. The Holistic Hair Fix program is built around this idea, connecting hair loss to hormonal imbalances, thyroid dysfunction, nutrient deficiencies, gut malabsorption, and inflammation, with a plan tailored to your labs, lifestyle, symptoms, and long-term wellness goals.
Q: Can stress alone cause hair loss?
A: Significant stress can trigger telogen effluvium, the diffuse shedding pattern described above. It's usually temporary, but it's worth ruling out thyroid, iron, and hormonal causes rather than assuming stress is the only factor.
Q: How long after a trigger does hair loss usually show up?
A: For telogen effluvium (postpartum, illness, crash dieting, thyroid changes), shedding often becomes noticeable two to three months later, due to the natural delay in the hair growth cycle.
Q: Is patchy hair loss always alopecia areata?
A: Not necessarily, but sudden, patchy hair loss is the classic presentation and is worth having examined. A provider can distinguish it from other causes with a scalp exam and, if needed, further testing.
Q: Should I just try biotin first?
A: Not without knowing your actual nutrient levels. True biotin deficiency is uncommon in people eating a normal diet, and high-dose biotin without a confirmed deficiency isn't well-supported for regrowth — it can also skew certain lab results.
Q: Can I have more than one cause at once?
A: Yes — this is common, not rare. An autoimmune thyroid condition, for example, can create a hormonal driver and a nutritional one simultaneously, which is why a broad lab workup matters more than treating a single suspected cause.
If you've been trying to figure out whether your hair loss is hormonal, nutritional, or autoimmune, you don't have to sort it out alone or guess your way through supplements. Dr. Sonza Curtis and the Three D Wellness team in Roswell, GA use advanced lab testing to look at the full picture — thyroid, nutrients, hormones, and inflammation — so your plan is built around what's actually happening in your body. Start with a free 15-minute Discovery Call to talk through your symptoms and next steps.
Three D Wellness is a functional medicine practice in Roswell, GA, led by Dr. Sonza Curtis alongside holistic health coach Heidi and weight-loss and nutrition coach Sharon Muse. Using advanced lab testing and a root-cause approach, the team works with patients on autoimmune disorders, hormonal imbalance, adrenal dysfunction, chronic fatigue, thyroid issues, digestive disorders, and hair loss — rather than treating symptoms in isolation.
Three D Wellness
555 Sun Valley Drive, Suite C1, Roswell, GA 30076
Phone: (678) 621-8100
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