What Is a Yeast Infection: Understanding Its Causes, Symptoms, Diagnosis & Prevention

Yeast infections are some of the most common infections in women, with over 2/3rd of all women contracting a yeast infection at least once in their lives. These infections are caused by common fungi called Candida albicans. The fungus is normally not harmful and resides in the body as a commensal, or harmless, organism. However, when the balance of various microbes in the body is thrown off, the fungus can cause an infection. Though not categorized as a sexually transmitted illness, a yeast infection can spread to an uninfected partner in case you have sex with them while you’re suffering from a yeast infection. 

How long can yeast infections last? Most yeast infections resolve quickly. We discuss various aspects of yeast infections, thoroughly detailing what is a yeast infection, common questions like ‘Can stress cause yeast infections?’, the various tests involved, its treatment, and how to prevent yeast infections from recurring in the upcoming sections. 

Symptoms of Yeast Infection

Yeast Infections: Vaginal, Penile, & Oral

  • When asking the question of what is a yeast infection, most people have vaginal yeast infections in mind, since they’re among the most common forms of yeast infections. However, yeast infections, though more prevalent in women, can also infect men and cause penile yeast infections. 
  • While vaginal yeast infections infect the vaginal tract and the vulva, leading to discharge and rash in most cases, penile yeast infections infect the superficial portions of the penis, causing white patches or redness. Some penile yeast infections are also not noticeable, making it a problem that takes a keen eye to identify unless itchiness and a burning sensation also accompany the superficial symptoms. 
  • Vaginal yeast infections have several causes, including bodily imbalance affecting the vaginal microbiome, prolonged antibiotic use, or a weak immune system. On the other hand, penile yeast infections are commonly caused by unprotected sexual contact with a partner that has an active yeast infection. 
  • If you’re wondering how long does a yeast infection last in the case of men, it’s about the same time as in women and can be resolved in about a week, provided the condition is addressed using the required antifungal treatment.   
  • Yeast infections can also affect the mouth in a condition called oral candidiasis, where the fungus can grow in patches either on the corners of the mouth or on the surface of the soft tissues of the mouth. This includes the inner parts of the cheek, the tongue, or the floor of the mouth. Oral yeast infections are also called oral thrush and often appear in people with weak immune systems or poor oral hygiene practices. 
  • Yeast infections, irrespective of the affected region, are often caused by the fungi from the genus Candida. 
  • Though this blog focuses primarily on vaginal yeast infections, it’s important to understand penile and oral yeast infections to understand the potential causes or transmission routes of the infection.

The Causes of Yeast Infections

Most women end up wondering how they caught the yeast infection after they begin noticing symptoms. Here’s a list of causes of vaginal yeast infections: 

  • Vaginal Microbiome Imbalances & Antibiotics

      • Like the gut, the vagina too harbors a vast population of microbes that contain several beneficial organisms and commensals. The vagina harbors over 581 species of bacteria alone. There also exist several organisms such as yeast and protozoa that remain harmless unless the microbiome is in imbalance. 
      • The vaginal microbiome is dominated by the Lactobacillus genus of bacteria which are beneficial and release several compounds that keep other potentially harmful microbes in check. 
      • Taking antibiotics or consuming them too frequently ends up killing these beneficial bacterial species too, allowing microbes like yeast to cause infections. 
      • The vaginal microbiome can also be thrown off during menstruation, in case you’re wondering ‘Why do I get a yeast infection after my period?’
  • Debilitating Diseases & Weak Immune Systems

      • Women with weak immunity brought upon by debilitating diseases such as uncontrolled diabetes, cancer, or AIDS are more prone to infections. 
      • Yeast infections are opportunistic and can present themselves the moment there is a vulnerability in the immune system. 
      • Yeast infections, both vaginal and oral, are common occurrences in women that suffer from diseases or syndromes that result in weak immunity.  
  • Pregnancy & Menstruation

      • Pregnant women are at a higher risk of developing yeast infections due to the hormonal activity occurring in their bodies. 
      • A high level of estrogen is linked to yeast overgrowth and can lead to yeast infections in women. 
      • This is also prevalent before the onset of menstruation as there are estrogen spikes and drops throughout the menstrual cycle, in case you’ve been wondering ‘Why do I get a yeast infection before my period?’
  • Stress & Psychological Causes

      • Stress is closely associated with immunity. The body releases the hormone cortisol when the body experiences stress. Cortisol suppresses the immune system and improves the availability of glucose in the bloodstream. 
      • Both of these conditions are ideal for improved growth of potential pathogens like the Candida yeast. 
      • So, can stress cause yeast infections? Certainly. Due to the decrease in immunity caused by the cortisol spike and the increased availability of nutrients in the blood, yeast infections are commonly noticed in women that complain of stress and psychological disturbances. 
  • The Connection to Oral Contraceptives

    • While oral contraceptives are not the direct cause of yeast infections, these medications can throw off hormonal levels such as those of estrogen. This can lead to an increased susceptibility to yeast infections in women. 
    • Oral contraceptives are also known to hamper the vaginal pH balance - another important cause of vulnerability to yeast infections. 
    • Like oral contraceptives, any form of hormone therapy that tends to increase the levels of estrogen is also linked as an indirect influence on yeast infections and the susceptibility to them in women. 

can stress cause yeast infection

Yeast Infection: The Symptoms

The symptoms of yeast infection are: 

  • Irritation and itching in the vagina and around the vulva
  • Burning sensation while urinating
  • Discomfort during sexual intercourse 
  • Vaginal soreness 
  • Either watery or thick white vaginal discharge that is clumpy and odorless 
  • Rashes in the vagina
  • Vulvar swelling and redness 

Speak to your physician in case you experience any of the above symptoms. 

How Long Does a Yeast Infection Last?

  • Yeast infections often resolve in about a week if they’re treated with the required medications. 
  • Yeast infections can also be self-limiting, and resolve on their own. So if you’re wondering how long can yeast infections last if not treated, the infection will resolve in 10 days if it’s an uncomplicated infection. 
  • On the other hand, complicated yeast infections can take up to 2 or 3 weeks to resolve on their own without treatment. However, it is always advisable to see your doctor and get the infection addressed as soon as possible. 
  • Yeast infections that cause extremely painful or itchy symptoms, alongside discomfort, must be reported to the physician at the earliest. 
  • So, what happens if a yeast infection goes untreated after all? While most common infections resolve by themselves, some infections can turn into severe infections that can lead to a serious full-body illness called systemic candidiasis. This can become life-threatening if not addressed on time.

How to Test for Yeast Infections & Diagnose Them

  • Most times, doctors will conduct a detailed pelvic examination and look for signs and symptoms as presented in a vaginal yeast infection. 
  • Diagnosis is often based on observational confirmations and correlations with medical, menstrual, and sexual history. 
  • As far as lab testing goes, if you have concerns about how doctors test for yeast infections, the process involves collecting a vaginal swab sample or a sample of discharge. Doctors can also recommend specific vaginitis tests to diagnose your condition.
  • The samples are examined under a microscope or cultured. Once the fungal species causing the infection is identified, the doctor will structure a specific treatment plan to address your yeast infection. 

Treating Yeast Infections

  • Most yeast infections are treated in a straightforward manner using several antifungal agents that are available as ointments, creams, suppositories, and oral antifungal tablets. 
  • For pregnant women, and for women suffering from debilitating conditions, the treatment protocol is often different and more comprehensive. 
  • Antifungal ointments and creams are also available over the counter, however, it is always advisable to have a doctor’s opinion before the commencement of the treatment. 

Yeast Infections & Other Diseases

  • It is common for people to become confused between other infections of the vaginal canal and yeast infections. 
  • In case you’ve been confused about how to tell if it’s a yeast infection or herpes, you aren’t alone. However, the differences between the conditions are quite marked. While herpes presents with classical blisters or raised fluid-filled bumps over a reddened area, yeast infections have red or white patches coupled with a cottage cheese-like clumpy discharge. 
  • Many women also experience confusion over what distinguishes bacterial vaginosis (BV) and yeast infections and often think about how to differentiate between BV and yeast infections. Since BV has similar symptoms, it can become quite complex to tell the difference between the two. 
  • BV can cause long-term complications such as premature delivery and infertility, whereas yeast infections do not. Also, the clumpy discharge is a classical feature of yeast infections and is an odorless discharge. On the other hand, discharge caused by bacterial vaginosis has a fishy odor and looks grayish white. 
  • Yeast infections can also be confused with urinary tract infections, however, the latter involves the urethra and can lead to kidney damage if left untreated. 


  • Avoid using aggressive cleaning and douching methods to clean the vagina. 
  • Have protected sex. 
  • Avoid wearing underwear that fits too tightly. 
  • Avoid wearing damp clothing such as swimsuits for too long. 
  • Use only water-based lubricants. 
  • Avoid taking antibiotics for viral diseases such as the common cold. 
  • Speak with your doctor if you have an irregular menstrual cycle. 
  • Get in touch with a mental health professional if you are dealing with stress and other mental health concerns. 

What is Yeast Infection


It’s important to see a doctor in case you have recurrent yeast infections, or if you have at least 4 instances of yeast infections in a year. Longstanding yeast infections that do not resolve even upon treatment also warrant immediate medical attention. Be sure to get in touch with your doctor and address your concerns to ensure you rest easy and can remain in the best of health.