What does an abnormal smear test result mean?

A smear test is often something that gets put off or avoided. But for women over 25, it’s a must. However, getting the test is the easy part – what happens if your test comes back with an abnormal result?

It’s worth knowing that in the UK, cervical screening now uses HPV primary testing. This means that the sample taken during your smear test is first checked for high-risk types of human papillomavirus (HPV) – the virus that can cause cervical cell changes. Only if high-risk HPV is detected will the same sample then be examined for abnormal cells. If no high-risk HPV is found, you won’t need further testing until your next routine screening.

So, what does an abnormal smear result mean?

It is understandable that you may get anxious if you receive a letter of referral to a colposcopy clinic because of abnormal smear test results.

The first thing to say is that the vast majority of women in your situation do not have cancer. Instead, this is a condition with changes in the neck of the womb (cervix) that we call CIN (Cervical Intraepithelial Neoplasia) – pre-cancerous changes. Pre-cancerous changes of the cells of the cervix are those that have the potential to turn into cancer if left untreated for some time.

What does an inadequate smear mean?

An unreadable or inadequate smear does not mean that your smear is abnormal. This is an inconvenience but should not make you worry. However, be aware that you will be called for a repeat cervical cytology sample in three months. Waiting for this time before repeating the test reduces the risk of a further inadequate sample.

There may be many reasons for inadequate smears. Difficulty in getting enough cells due to menopausal changes in the cervix and complex problems in processing the cells can be possible causes. Sometimes your doctor or practice nurse can advise a treatment that may make taking a further sample more effective – such as vaginal oestrogen cream if the inadequate smear is due to postmenopausal changes, or antibiotics if an infection is present.

What are the different types of abnormal smear?

There are two groups of cells on the cervix – outer cells which are called ectocervical or squamous cells and inner cells also called glandular/columnar or endocervical cells. Abnormalities can occur in both groups of cells but are much more common in the outer or squamous cells (called dyskaryosis on smear and CIN on a tissue biopsy).

Squamous cell abnormalities

Smears are graded with differing degrees of abnormality, from a non-specific ‘borderline’ change to low-grade and high-grade changes called dyskaryosis (the medical term for abnormal cells). Low-grade smears are likely to return to normal over a period of time in the majority of women. High-grade smears have a small chance of progression to cervical cancer, if left untreated. This may take more than 10 years.

Glandular cell abnormalities

Sometimes a smear result will come back as atypical glandular cells, meaning the abnormality is in the glandular or columnar cells of the cervix. In this case, you will be referred either directly by the laboratory or by your smear taker to a colposcopy clinic.

What are the reasons for these abnormal cells?

The vast majority of cervical cell abnormalities are caused by infection with a virus called HPV (Human Papilloma Virus). Most women and men get this infection at some point in their lives but clear it spontaneously. In a minority of women, if the infection persists for a long time, it can lead to cervical cell changes.

I have an abnormal smear. What is the chance that I have cancer?

Whilst about 1 in 20 women will have a smear test result which is abnormal, only about 1 in 2000 will have cervical cancer. That means approximately 1% of women with any grade of abnormal smear will have a cancer. So statistically speaking, the risk that you have already developed cervical cancer is very small, even if your smear is abnormal.

However, we realise that women worry about this possibility – and this is where colposcopy is helpful. In the majority of women, the colposcopy is very reassuring as it provides a clearer picture of the situation. The colposcopist will be able to assess the size and grade of abnormality and plan the next steps for management.

Written by Miss Sanjay Kumari, Consultant Obstetrician and Gynaecologist

This blog was last reviewed in June 2025 by:

• Miss Shree Datta, Consultant Obstetrician and Gynaecologist
• Dr Amelia Davison, Consultant Obstetrician and Gynaecologist