2 August 2023

6 reasons for low energy levels in females

6 reasons for low energy levels in females
Medically reviewed by Dr Leah Gorodi, MBChB, MRCGP, Dip BSLM

We live in a fast-paced world, and finding time to rest can be challenging. It’s no wonder that feeling fatigued and lacking energy is common among women.

If you've been feeling noticeably tired and can't figure out why, it's essential to rule out pregnancy first. It's common to feel very tired or even exhausted during pregnancy. This is because your hormones are changing dramatically, and can leave you craving a nap.

However, if you’re confident you’re not pregnant, let’s dive into 6 of the most likely reasons you’re feeling a regular slump in energy. We’ll cover thyroid dysfunction, low iron levels, type 2 diabetes, and vitamin deficiencies.

You can also take H&B&Me’s Energy blood test, which tests for all 6 potential causes we discuss below, and gets you doctor-reviewed results in 48 hours.

1. Underactive thyroid

An underactive thyroid is a common health issue that can cause low energy in women (1). The thyroid gland produces thyroid hormone, which regulates your metabolism (the body’s process of converting food and drink into energy).

An underactive thyroid, also known as hypothyroidism, can lead to various symptoms, including fatigue, weight gain, and depression (1). Hypothyroidism is significantly more common in females than males. You can take an advanced thyroid test to learn more about your thyroid function.

2. Low iron levels

Low iron levels are a major culprit for tiredness in females and are commonly characterised by extreme fatigue and weakness. Iron is essential for producing healthy red blood cells that carry oxygen throughout your body without trouble.

A lack of iron can lead to iron deficiency anaemia, which women are particularly susceptible to due to blood loss during menstruation.

You can understand your body’s unique iron levels by using a reliable test. Unnecessary supplementation with iron tablets can be dangerous for your organs and result in nausea or other nasty side effects (2), so you need to know your levels and discuss them with a doctor before you start supplementing.

It's important to note that iron deficiency anaemia requires medical investigations to work out the underlying cause and the correct treatment. There are more serious causes of low iron levels, so it's important to see a doctor to assess any signs or symptoms of low iron.

3. Type 2 diabetes

Type 2 diabetes is a serious health condition that causes your blood sugar to become too high. It’s where your body can’t make enough insulin or use insulin properly, which is different from type 1 diabetes (an autoimmune condition).

If type 2 diabetes isn’t recognised and treated quickly, it can cause serious damage to your organs, affecting your mobility and even your eyesight.

Feeling tired all the time is one of the main symptoms of diabetes. Other signs of the condition include feeling unusually thirsty, blurred vision, and needing to pee more often than usual.

Being overweight is also a common risk factor for diabetes, so it’s important to try and stay within a healthy weight range. You can check if you may be at risk for diabetes with this quick test.

4. Vitamin D deficiency

Vitamin D is essential for healthy bones, fighting infections and general well-being. It's known as 'the sunshine vitamin' because sun exposure is the main way your body produces it.

Not many foods provide your body with vitamin D, so supplementation is often recommended – especially during the winter if you work indoors or wear high-coverage clothing.

Being deficient in vitamin D is linked with low energy levels. On top of that, there’s even a correlation between low vitamin D and l sleep disorders, which could mean less rest, lower sleep quality or general sleepiness (3).

The good news is that if you're low in vitamin D, supplementation can make you noticeably less tired and fatigued (4). You can check your vitamin D levels with H&B&Me's quick finger prick test.

5. Vitamin B12 deficiency

Unlike vitamin D, vitamin B12 is naturally found in many foods. However, these are mainly animal foods, like meat, fish, and dairy, so you're at higher risk of vitamin B12 deficiency if you eat a vegan diet.

Extreme tiredness and low energy are two main symptoms of vitamin B12 deficiency, alongside mouth ulcers, breathlessness, pale skin, headaches, and sensory disturbances like pins and needles.

Like iron, vitamin B12 is essential for making healthy red blood cells that function properly. These cells carry oxygen around your body, so if they're not working correctly, your body doesn’t get the oxygen it needs. This is anaemia, and it can make you feel pretty exhausted (5).

To get insights into your vitamin B12 levels, you can take a quick finger prick test.

6. Folate deficiency

Folate, also known as vitamin B9, has similar functions to B12. It plays a vital role in cell production, growth, and nerve health.

Folate is common in many foods, like leafy green vegetables and citrus fruits.
However, your body doesn’t store folate in large amounts, so your levels can quickly drop after only a few weeks of eating a low-folate diet. So if you’ve neglected your kale intake over the last month or so and feel relentlessly tired, you might be at risk of a deficiency.

On top of tiredness, other folate deficiency symptoms include mouth ulcers, pale skin, and shortness of breath. Folate levels are one of the biomarkers measured in our advanced vitamin test.

Finally, if you're pregnant, monitoring your folate levels is even more important, as it helps prevent congenital disorders (6).

The final word

Low energy levels and unusual tiredness in females can be due to many reasons, such as pregnancy, an underactive thyroid, low iron levels, type 2 diabetes, and deficiencies in vitamins D, B12, and folate.

It's essential to uncover the root cause of your fatigue so you can effectively and safely address it. H&B&Me's Energy blood test offers a simple, quick, and reliable solution to help you pinpoint the underlying issue.

With doctor-reviewed results for all 6 potential causes of tiredness outlined in this article available within 48 hours, you'll have the knowledge to tackle your energy slump and bring back your zest for life.


An important reminder: Low energy and tiredness can be related to more serious conditions than those discussed in this article. H&B&Me's energy test does test for some important conditions related to tiredness, but not all of them. If you have persistent, unexplained tiredness for more than 4 weeks, you must go and see your GP.


1. Thyroid Functioning and Fatigue in Women With Functional Somatic Syndromes – Role of Early Life Adversity


2. The Clinical and Biological Manifestations in Women with Iron Deficiency Without Anemia Compared to Iron Deficiency Anemia in a General Internal Medicine Setting: A Retrospective Cohort Study


3. The Association between Vitamin D Deficiency and Sleep Disorders: A Systematic Review and Meta-Analysis


4. Effect of vitamin D3 on self-perceived fatigue


5. Vitamins and minerals for energy, fatigue and cognition: A narrative review of the biochemical and clinical evidence


6. Folate supplementation for prevention of congenital heart defects and low birth weight: an update


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