Causes of Candidiasis (Thrush)

NewsGuard 100/100 Score

Candida infection is a fungal infection caused by yeast.

Candida species, over 20 in number, are normal inhabitants of the mouth, throat, vagina and other mucosal surfaces like the gastrointestinal tract. These are small in number and do not cause harm.

Sometimes they may multiply to cause infections. Commonest culprit is the Candida albicans species. (1)

In women, yeast infections are one of the commonest reasons for vaginal discharge, burning, stinging and itching.

These yeasts are a part of the normal environment of the vagina. Infection occurs when there is a disbalance of this environment causing them to multiply.

The disbalance may be due to change in acidity of the vagina or the hormonal balance of the vagina. This is the commonest cause for infection.

80-90% cases are caused by Candida albicans.

Common causes of Candidiasis

Common causes of thrush include pregnancy, menstruation, birth control pills, diabetes, steroid or antibiotic use.

After menopause there is a heightened risk of candida infections.

Those with a weak immunity are also prone to vaginal candidiasis.

Candida infections rarely may also be passed from person to person via unprotected sexual intercourse. (2)

Causes of Invasive Candidiasis

Invasive candidiasis occurs when there is suppressed immunity. This leads to multiplication of the candida that the person harbors normally and their entry into the blood stream.

Candida in invasive candidiasis may also be acquired from medical devices like intravenous (IV) catheters etc. (2)

Candidiasis risk factors

Risk factors that raise the possibility of getting candidial infections include (3) –

  • Taking antibiotics – The vagina and gastrointestinal tract is colonized by friendly bacteria called commensal organisms. Taking antibiotics kill these and alter the normal environment that allows unchecked growth of the yeast.
  • Taking steroids – Steroids suppress the immunity and may allow candidial growth.
  • Pregnancy.
  • Diabetes – There is too much sugar in the blood and a weakened immunity that raises the risk of thrush.
  • Weak immune system due to diseases like AIDS, blood and other cancers. In cancers chemotherapy is a cause behind thrush. Since immunity is low the person is unable to fight of the yeast infection.
  • Elderly with low immunity.
  • New born babies especially if they are born with a low birth weight.

Further Reading

Last Updated: Jun 8, 2023

Dr. Ananya Mandal

Written by

Dr. Ananya Mandal

Dr. Ananya Mandal is a doctor by profession, lecturer by vocation and a medical writer by passion. She specialized in Clinical Pharmacology after her bachelor's (MBBS). For her, health communication is not just writing complicated reviews for professionals but making medical knowledge understandable and available to the general public as well.


Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Mandal, Ananya. (2023, June 08). Causes of Candidiasis (Thrush). News-Medical. Retrieved on May 29, 2024 from

  • MLA

    Mandal, Ananya. "Causes of Candidiasis (Thrush)". News-Medical. 29 May 2024. <>.

  • Chicago

    Mandal, Ananya. "Causes of Candidiasis (Thrush)". News-Medical. (accessed May 29, 2024).

  • Harvard

    Mandal, Ananya. 2023. Causes of Candidiasis (Thrush). News-Medical, viewed 29 May 2024,


The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
Post a new comment

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.

You might also like...
Saliva substitute from University of Leeds scientists offers major relief for dry mouth conditions