Archive · 28 Aug 2026
Mildly High Blood Sugar May Raise Fungal Infection Concerns
A little high blood sugar does not mean someone will definitely get a fungal infection.
The clearest link is seen in people with diabetes or poorly controlled blood sugar.
If glucose stays high, some parts of the immune system may not work as well.
Extra glucose may also help fungi such as Candida grow.
Fungal infections can affect the mouth, genitals, skin, feet, and nails.
Infections that keep coming back or take a long time to go away may be worth discussing with a doctor.
Doctors may check blood sugar with fasting glucose or an HbA1c test.
Sometimes they may use an oral glucose tolerance test for more information.
Recurrent fungal infections alone do not prove that a person has prediabetes or diabetes.
Mildly elevated blood sugar does not automatically cause fungal infections, with the strongest evidence involving established or poorly controlled diabetes.
Persistently high glucose may impair immune cells and support the growth and adherence of organisms such as Candida.
Infections associated with elevated blood sugar include recurrent genital or oral candidiasis, skin, foot and nail infections, athlete’s foot, and ringworm.
Recurrent, unusually persistent, or treatment-resistant fungal infections may justify discussing blood sugar testing with a doctor.
Suggested tests include fasting plasma glucose and HbA1c, with an oral glucose tolerance test sometimes providing additional information.
- Who
- People with mildly elevated blood sugar and those experiencing recurrent or persistent fungal infections; Dr Palleti Siva Karthik Reddy provided the expert comments.
- What
- The article examines whether mildly elevated blood sugar can increase susceptibility to fungal infections and when testing may be appropriate.
- When
- The article refers to recurrent or unusually persistent infections and cites the 2026 American Diabetes Association criteria.
- Where
- The expert comments were provided to indianexpress.com; specific infection sites include the mouth, genitals, skin, feet, and nails.
- Why
- Persistently elevated glucose may impair immune cells and encourage the growth or adherence of fungi, although mild elevation alone does not establish a cause.
- Expert
- Dr Palleti Siva Karthik Reddy, consultant physician at Elite Care Clinic
- Commonly discussed infections
- Candidiasis, skin, foot and nail infections, athlete’s foot, and ringworm
- Initial blood sugar tests
- Fasting plasma glucose and HbA1c
- Additional test
- A 75 g oral glucose tolerance test may provide more information when results are borderline or suspicion remains
- Prediabetes HbA1c range
- 5.7%–6.4%, according to the criteria cited in the article
- Prediabetes fasting glucose range
- 100–125 mg/dL, according to the criteria cited in the article
- Prediabetes two-hour glucose range
- 140–199 mg/dL during an oral glucose tolerance test, according to the criteria cited in the article