Symptoms of low thyroid

A simple guide to understanding the signs your thyroid may be underactive.

The thyroid is a small gland at the base of your neck, but it plays a major role in your metabolism, energy, hormone balance, and overall sense of wellbeing. When thyroid function slows down — even slightly — it can affect many systems in the body.

Below are the most common and meaningful symptoms of low thyroid function. Even having just a few of these symptoms can indicate that your thyroid deserves attention.

1. Energy & Metabolism

   These are often the first symptoms people notice.

   • Persistent fatigue or low stamina

   • Feeling cold easily, especially hands or feet

   • Low basal body temperature

   • Weight gain or difficulty losing weight despite healthy habits

2. Cognitive & Mood Changes

   Thyroid hormones directly influence brain function.

   • Brain fog or slow thinking

   • Memory lapses

   • Low motivation

   • Depressed or “flat” mood

3. Hair, Skin & Nails

   Slow thyroid affects growth and repair.

   • Hair shedding or thinning

   • Dry, rough, or flaky skin

   • Brittle nails

   • Thinning of the outer eyebrows

4. Digestion & Body Systems

   Low thyroid slows everything down.

   • Constipation or slow digestion

   • Bloating

   • Low heart rate

   • Low blood pressure

   • Elevated cholesterol

5. Reproductive & Hormonal Changes

   Thyroid and reproductive hormones are closely connected.

   • Irregular menstrual cycles

   • Heavy periods

   • Low libido

   • Difficulty conceiving

6. Muscles & Joints

   • Muscle weakness

   • Aches, stiffness, cramping

7. Other Common Signs

   These can be subtle, but meaningful.

   • Puffy face or swollen eyelids

   • Hoarse voice

   • Carpal-tunnel-type symptoms

   • Slowed reflexes

When to Seek Testing

If you recognize several of these symptoms — or if they’ve been gradually building over time — it’s reasonable to have your thyroid evaluated. Testing typically includes TSH, Free T4, Free T3, and thyroid antibodies, depending on your symptoms and history.

Early detection matters. Even mild slowing can impact mood, energy, metabolism, and long-term health.

If you’d like support assessing your symptoms or exploring treatment options, please book a consultation.