Underactive thyroid symptoms in females

What is an underactive thyroid?

An underactive thyroid, also known as hypothyroidism, is a condition where the thyroid gland fails to produce enough thyroid hormones. This small, butterfly-shaped gland in the neck plays a big role in regulating metabolism, energy levels and many vital body functions.

In females, this condition is particularly significant as it can affect reproductive health, menstrual cycles and mood. When the thyroid doesn’t function properly, many systems in the body slow down. Left unmanaged, it may lead to more serious complications like infertility, heart issues or goitre.

Which symptoms signal low thyroid function in females?

Symptoms of an underactive thyroid in females often start mildly but become more noticeable over time. Common signs include:

• Constant tiredness or fatigue
• Weight gain despite no major lifestyle changes
• Cold sensitivity
• Dry skin and brittle hair or nails
• Depression or low mood
• Slow heart rate
• Constipation
• Memory issues or difficulty concentrating (‘brain fog’)
• Menstrual irregularities or heavier periods
• Fertility challenges
• Puffy face or hoarseness
• Thinning eyebrows, especially outer edges
• Muscle weakness or cramps
• Swelling in the neck (goitre)

Why does hypothyroidism develop — and what triggers it?

The most common cause of underactive thyroid in females is autoimmune disease, particularly Hashimoto’s thyroiditis, where the immune system attacks the thyroid gland.

Other causes include:

Medical treatments:

• Radiation therapy to the neck or head
• Thyroid surgery
• Certain medications (e.g. lithium, amiodarone)

Nutritional factors

• Iodine, selenium, zinc, iron, and vitamin D deficiency
• Celiac disease
• Gluten intolerance/non coleiac gluten sensitivity

Gut issues

• Gut dysbiosis
• Leaky gut
• H Pylori, candida or SIBO ( small intestinal bacterial overgrowth) infections

Hormonal changes

• Pregnancy and postpartum thyroiditis
• Perimenopause and menopause
• Estrogen dominance
• Low progesterone

Chronic Stress

• Adrenal fatigue
• Weakened immune system

Genetics & other conditions

• Family history of thyroid disorders
• Pituitary gland dysfunction
• Congenital hypothyroidism (present at birth)

Toxic Overload

• Endocrine disruptors like BPA, plastics, pesticies, flouiride and mercury

Poor liver function

• the liver is necessary to convert T4 to T3

 Chronic infections

• Epstein barr virus
• Lyme disease
• Mold exposure

How is an underactive thyroid diagnosed with functional lab testing?

Our functional medicine specialist will start with a thorough assessment and discussion of symptoms. Our advanced lab tests provide valuable insights, including:

• TSH (Thyroid-Stimulating Hormone): Often elevated in hypothyroidism.
• Total T4: Measures the total amount of thyroxine in the blood, both bound and unbound.
• Free T4 (Thyroxine): Usually low in underactive thyroid.- hypothyroidisms
• Free T3: The active form of triiodothyronine, often low in hypothyroidism
• TPO antibodies: May be checked to confirm autoimmune origin (e.g. Hashimoto’s).
• TgAB (Thyroglobulin Antibodies): Can indicate an autoimmune thyroid condition.

Regular monitoring is important to adjust hormone levels over time as the body heals and treatment begins.

What lifestyle changes and supplements support thyroid health?

Living with an underactive thyroid can be managed effectively with the correct  habits and lifestyle changes. Here’s how to support thyroid health:

• Get regular Thyroid blood checks, especially if you’re at risk (family history, over 60, postpartum, Coeliac disease, IBS, or have had chronic infections / viruses such as Epstein Barr).
• Eat a whole foods diet, remove processed food and supplement with, selenium, zinc, vitamin D and zinc.
• Exercise regularly to help manage weight and energy levels.
• Avoid self treating with supplements without testing for deficiencies first .
• Keep track of your menstrual cycle and mental health – changes may signal hormonal shifts.
• Test for leaky gut, dysbiosis, pathogens and heavy metals.
• Monitor Blood Sugar
• Cleanse the liver and detoxify the body.

How is hypothyroidism managed — and what role does medication play?

An underactive thyroid is typically managed with daily hormone replacement, most commonly levothyroxine, a synthetic version of T4. This helps restore normal hormone levels and relieve some symptoms.

Adjustments are gradual and based on lab test results, with follow-ups every 3 months until levels stabilise. Most people need lifelong support but can live well with the condition.

In addition to medication, lifestyle changes such as maintaining a healthy diet, stress management and regular exercise are often recommended.

How does our root-cause method restore thyroid balance naturally?

If you’re navigating symptoms of an underactive thyroid, we’re here to help you identify the root cause and find balance again. Our approach focuses on:

• Root cause healing- not treating symptoms with medication.
• Personalised support with ongoing health assessments and 24/7 access to your practitioner
• Healing your Gut, hormones, immune system, digestion, detoxification, energy production and nervous system- all key aspects which contribute to thyroid dysfunction.
• Bespoke health plans addressing diet, rest, exercise, stress reduction detoxification and supplementation.
• Regular check-ins and digital health tools
• Easy-to-understand results and recommendations