Can subclinical hypothyroidism (slightly elevated TSH levels, normal T4 levels) cause hair thinning/loss?

Confusingly, both hypothyroidism and hyperthyroidism can induce similar changes in the physiology of the skin and the hair follicle.
Hypothyroidism will cause myxedema, which is a mucinous edema of the dermal tissue due to the extracellular deposition of a mucopolysaccharide-protein complex, loss of the lateral 1/3 of the eyebrows and diffuse thinning of the scalp. Τ3 deficiency, which has been shown to increase sebum excretion in lab animals probably pushs the hair follicle into premature resting phase, often resulting in a massive hair loss and thinning of hair.
Please consult your endocrinologist to treat your thyroid disease and you can add FDA-approved drugs in your scheme to combat hair loss.

Subclinical hyperthyroid or hypothyroidism can cause hair loss. The receptors in the follicles are significantly more sensitive than our blood tests. Hair loss in women is often multifactorial. Find a hair loss expert who can coordinate your diagnosis and suggest a treatment plan.Jeff Rapaport MDCore Aesthetic Realself

Hormones and stress play a major role in hair retention or loss. Your thyroid levels are indeed a likely contributor to your hair loss. I share your concerns regarding products such as levothyroxine.
I encourage you to find a physician practicing Functional or Integrative Medicine that also practices Bio-Identical Hormone Replacement Therapy. They are experts at treating your metabolic and nutritional needs as near naturally as possible absent the side effects. 
Wishing you the best.
Warmly,
Arbella Sarkis MD  

Thank you for your question.  Both hypo and hyperthyroidism, including subclinical, can cause hair loss.  The body, and especially the hair, is much more sensitive to changes in the thyroid then the numbers from our blood work reflect.  I would recommend seeing a physician you are comfortable with as there are numerous approaches to hair loss based on the multi factorial nature of hair loss.  It may be as simple as supplements, thyroid supplementation (We recommend nature thyroid or armour over synthroid), PRP injections, or may be as extensive as hair transplantation.

Dear Guitarist4342,Hello and thank you for your excellent question. Yes, subclinical hypothyroidism can result in hair loss. I suggest that you start Finasteride and Minoxidil, as they are the only two medications for hair loss approved by the FDA. For women of child-bearing age, I use spironolactone instead of finasteride. Both medications have different mechanism of action, and I usually recommend both medications to my patients. Other adjuncts include low-level laser light therapy, PRP, stem cell, or other regenerative medical treatment. Also, you will want to ensure that you are not taking any medications that could be contributing to your hair loss. The main objectives with the combination treatments are to stabilize your hair loss, increase your existing hair fiber diameter, and stimulate some hair regrowth. After those options are completed, I recommend hair transplant, including FUE or FUT. It is best to answer your question during a face-to-face evaluation, when you can discuss your goals and expectations for the procedure, and you can have a physical examination to evaluate for that procedure. I recommend that you find a board-certified, or board-eligible plastic surgeon with whom you are comfortable. Be sure to have all of your questions answered during a face-to-face meeting with your surgeon, and review before and after pictures of similar patients whom have had this procedure. If you have any questions, call our office for assistance. Good luck!

Best,

Jon Ver Halen, MD FACS

Harvard educated plastic surgeon

Texas “Top Doc” 2017, 2018

RealSelf100

America’s Top Plastic Surgeons, Consumer’s Research Council, 2010 – 2018
BeautyAdvisor Top Contributor

Hypothyroidism and hyperthyroidism both can cause hair loss. Meet with your primary doctor and discuss this