"Tired all the time" might be the least specific sentence in medicine — and one of the most common reasons people walk into our office. It is also where single-test thinking fails most often, because two of the biggest suspects share almost the same symptom list: the thyroid and the sex hormones.
The symptoms overlap almost completely. An underactive thyroid can cause fatigue, weight gain, brain fog, low mood, hair thinning, feeling cold, and low libido. Perimenopause and menopause can cause fatigue, weight gain, brain fog, low mood, hair changes, and low libido. Reading that list, no one — patient or provider — can reliably sort out which system is involved from symptoms alone. Testing is not optional here; it's the only way through.
The thyroid basics, and their limits. The thyroid is the body's metabolic thermostat, and the standard first test is TSH, a signal from the brain to the thyroid. A thorough evaluation often adds free T4 and free T3 (the hormones themselves) and thyroid antibodies, which can reveal autoimmune thyroid disease — Hashimoto's — the most common cause of low thyroid function and one that is especially common in midlife women. A single "normal" TSH with ongoing symptoms is a reason to look deeper, not a full stop.
Why "both" is a common answer. These systems do not operate in isolation, and they often change at the same stage of life. Thyroid disease becomes more common with age; perimenopause arrives in the same decades; and each can amplify the other's symptoms. Estrogen shifts can even affect how thyroid hormone is carried in the blood. Plenty of patients genuinely have a thyroid issue and a hormone transition happening at once — treating only one explains why "we fixed your thyroid" sometimes still leaves someone exhausted.
What else belongs on the list. An honest fatigue workup doesn't stop at two systems. Low iron or ferritin, low B12 or vitamin D, blood sugar and insulin problems, sleep apnea and other sleep disorders, depression, and certain medications all cause fatigue, and several of them commonly travel with hormone changes. The point of a curated panel is not to test everything imaginable — it's to test the plausible, in a pattern that can actually be interpreted.
What a good evaluation looks like. History first: when the fatigue started, how it behaves, what else changed with it. Then labs chosen for that story, reviewed with you in context — your symptoms next to your numbers — and a plan that addresses what was actually found, with follow-up to confirm it's working.
At Viona Vitality in Roseville and Lincoln, "tired all the time" gets a real workup: thyroid, hormones, and the metabolic and nutrient pieces that connect them. If you've been told to just live with it, a second, more complete look is reasonable. [Call (916) 262-7963]
This article is general health information and is not medical advice for any individual.