BPR
Blood tests by group

Blood tests for women from 30 to 39

Low iron and a slow thyroid are more common in women, and their signs look like many other things. A blood test shows the numbers, so you and your GP can act on them.

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Watch: the why in a minute

Women 30 to 39

1 minute 7 seconds

Why it makes sense at this stage

What the research supports, with the source of each point at the bottom of the page.

  1. 01

    Low iron is most common in women before the menopause

    Heavy periods and pregnancy are very common causes. Low iron can matter before anaemia shows, and your GP will often ask for a blood test if your periods are heavy.[1, 2, 3, 4]

  2. 02

    A slow thyroid is more common in women, and often starts between 30 and 50

    In a 20 year UK study, women had 3.5 new cases per 1,000 a year, against 0.6 in men. The symptoms look like many other things; a TSH and T4 blood test shows how your thyroid is working.[5, 6]

  3. 03

    High cholesterol gives no symptoms, and some of it runs in families

    The only way to know your level is a blood test. About 1 in 250 people have a type of high cholesterol that runs in families.[7, 8]

  4. 04

    Low vitamin D is common in UK winters

    From October to early March, sunlight in the UK is not enough to make vitamin D. In a UK winter study, 22 of 30 healthy adults were under 50 nmol/L.[9, 10]

  5. 05

    Type 2 diabetes can start early, often without symptoms

    The NHS lists a higher risk from 25 for people of South Asian, Chinese, Black African or Black Caribbean background, and says not everyone has symptoms.[11]

The tests and why

What usually makes sense for this group. Your GP can tell you what fits your own case.

Ferritin and full blood count

Low iron is common before the menopause, especially with heavy periods. Ferritin shows your stores; the blood count shows anaemia.[1, 2, 3, 4]

When to repeat: If low, as your GP advises.

TSH and free T4 (thyroid)

An underactive thyroid is more common in women and often starts between 30 and 50. Its symptoms can look like many other things.[5, 6]

When to repeat: If you have symptoms, or as your GP advises.

Cholesterol profile

High cholesterol does not usually cause symptoms, and about 1 in 250 people have a type that runs in families.[7, 8, 12]

When to repeat: As your GP advises. The NHS Health Check starts at 40, every 5 years.

HbA1c (average blood sugar)

Type 2 diabetes can start from 25 in some ethnic groups, often without symptoms.[11]

When to repeat: As your GP advises.

Vitamin D, 25(OH)D

From October to early March, UK sunlight is not enough to make vitamin D. Late winter shows your lowest level.[9, 10, 13]

When to repeat: Once in late winter.

Vitamin B12 (vegan or strict vegetarian diet)

A vegan diet without B12 supplements is a known cause of low B12.[14]

When to repeat: Once a year on a vegan diet.

Sexual health screen

Most people with chlamydia have no symptoms. The NHS suggests a test once a year or with a new partner.[15]

When to repeat: Once a year, or with a new partner.

What a blood test can and cannot do

It can

  • Show your iron stores, even before anaemia shows
  • Show how your thyroid is working, with TSH and T4
  • Give you a baseline for cholesterol, blood sugar and vitamin D

It cannot

  • Explain tiredness, weight gain or hair loss by itself: iron and thyroid are factors among many
  • Show your fertility: if you are planning a baby, see that group
  • Tell you to take iron: supplements without a measured lack are your GP's call

Tests that cover these markers

Not sure which one? The guided check-up suggests a starting point in a few questions.

Find your check-up

Prices are in the app, once you have an account.

What to do with your result

Your result arrives in your account, with reference ranges. A value outside the range, or a symptom with a normal result, is a conversation with your GP: treatment and supplements are their call. Repeat the same test later to compare.

Take the guide with you

The reasons, the tests and every reference, in a few pages. Free to download, no email needed.

Guide in English (PDF) Guide in Portuguese (PDF)

See also

References

  1. 1.Pasricha SR, Tye-Din J, Muckenthaler MU, Swinkels DW. Iron deficiency. Lancet. 2021;397:233-248. doi:10.1016/S0140-6736(20)32594-0 PMID 33285139.
  2. 2.Scientific Advisory Committee on Nutrition. Iron and Health. Public Health England. 2011. www.gov.uk/government/publications/sacn-iron-and-health-report
  3. 3.NHS. Iron deficiency anaemia. nhs.uk. 2026. www.nhs.uk/conditions/iron-deficiency-anaemia/
  4. 4.NHS. Heavy periods. nhs.uk. 2026. www.nhs.uk/conditions/heavy-periods/
  5. 5.NHS. Underactive thyroid (hypothyroidism). nhs.uk. 2026. www.nhs.uk/conditions/underactive-thyroid-hypothyroidism/
  6. 6.Vanderpump MP, Tunbridge WM, French JM, et al. The incidence of thyroid disorders in the community: a twenty-year follow-up of the Whickham Survey. Clin Endocrinol (Oxf). 1995;43:55-68. doi:10.1111/j.1365-2265.1995.tb01894.x PMID 7641412.
  7. 7.NHS. High cholesterol. nhs.uk. 2026. www.nhs.uk/conditions/high-cholesterol/
  8. 8.Akioyamen LE, Genest J, Shan SD, et al. Estimating the prevalence of heterozygous familial hypercholesterolaemia: a systematic review and meta-analysis. BMJ Open. 2017;7:e016461. doi:10.1136/bmjopen-2017-016461 PMID 28864697.
  9. 9.NHS. Vitamin D. nhs.uk. 2026. www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/
  10. 10.Close GL, Russell J, Cobley JN, et al. Assessment of vitamin D concentration in non-supplemented professional athletes and healthy adults during the winter months in the UK: implications for skeletal muscle function. J Sports Sci. 2013;31:344-353. doi:10.1080/02640414.2012.733822 PMID 23083379.
  11. 11.NHS. Type 2 diabetes: symptoms. nhs.uk. 2026. www.nhs.uk/conditions/type-2-diabetes/symptoms/
  12. 12.NHS. NHS Health Check. nhs.uk. 2026. www.nhs.uk/tests-and-treatments/nhs-health-check/
  13. 13.Scientific Advisory Committee on Nutrition. Vitamin D and Health. Public Health England. 2016. www.gov.uk/government/publications/sacn-vitamin-d-and-health-report
  14. 14.NHS. Vitamin B12 or folate deficiency anaemia: causes. nhs.uk. 2026. www.nhs.uk/conditions/vitamin-b12-or-folate-deficiency-anaemia/causes/
  15. 15.NHS. Chlamydia. nhs.uk. 2026. www.nhs.uk/conditions/chlamydia/

General information, not personal medical advice. Talk to your GP about your own situation. Questions: write to [email protected] or message us in the app.