Dr Clinton Colaco

Dr Clinton Colaco

Infectious Diseases Physician, with additional training in General and Acute Medicine

In my clinical practice I have many patients coming in with urogenital symptoms - confused if they have an STI (Sexually Transmitted Infection) or an UTI (Urinary Tract Infection).

Though these two conditions can sometimes have overlapping symptoms in females (for example, pain while urinating), they are distinct conditions with different causes and other very specific symptoms.

It’s crucial to get the right diagnosis from a medical professional so they can provide the right treatment for you.

Symptoms of STIs in Females

STIs are caused by various types of bacteria, viruses, or parasites. In my clinical practice, the STIs I most commonly treat include chlamydia, gonorrhoea, herpes, HIV, and HPV. Symptoms vary depending on the type of STI, but some common symptoms in females include:

  • Unusual vaginal discharge: Often with an unusual colour, smell, or consistency.
  • Pain during intercourse: Discomfort or pain during sex.
  • Genital itching or irritation: Itching, burning, or irritation in the genital area.
  • Painful urination: This can sometimes overlap with UTI symptoms.
  • Bleeding between periods: Unusual bleeding outside of the normal menstrual cycle.
  • Blisters or sores: In the case of herpes, for instance, blisters or sores may appear in the genital area.
  • Pelvic pain: Especially in more advanced stages of certain STIs like chlamydia and gonorrhoea.

Symptoms of UTIs in Females

UTIs are typically caused by bacteria (usually E. coli) entering the urinary tract. The symptoms include:

  • Frequent urination: An increased urge to urinate.
  • Burning sensation during urination: Pain or a burning sensation while urinating.
  • Cloudy urine: The urine may appear cloudy or have a strong smell.
  • Blood in the urine: Haematuria, or blood in the urine, can occur.
  • Pelvic pain: Pain in the lower abdomen or pelvis.
  • Feeling of incomplete bladder emptying: The sensation that the bladder is not fully emptied after urination. 

Key Differences

Due to overlapping symptoms, it is important to establish a proper diagnosis of a condition you may have. Talk with your healthcare professional and make sure you share all the symptoms you are experiencing. Generally, STIs and UTIs can be distinguished from each other by the following symptoms:

  • Discharge: Vaginal discharge is more commonly associated with STIs.
  • Sores or blisters: These are typically associated with STIs like herpes and not with UTIs.
  • Pain during intercourse: More common in STIs.
  • Type of pain: UTIs usually cause pain during urination, while STIs can cause a broader range of genital discomfort.

I see patients that have been misdiagnosed with STIs when they have UTIs and vice versa. It's important to note that both STIs and UTIs require medical attention. STIs can lead to serious health problems if left untreated (e.g. Pelvic inflammatory disease, infertility), and UTIs can escalate into more severe kidney infections (e.g. Pyelonephritis or Urosepsis).  In my experience, patients presenting with severe infections are often the result of not seeking timely medical attention, co-morbidities (e.g. Diabetes and being on UTI-causing medications), lifestyle factors, lack of barrier protection, consulting Dr Google’, and self-medicating particularly with previous (or expired) courses of antimicrobials. Due to the nature of these conditions, women are sometimes hesitant to ask for professional help and prefer to self-diagnose and self-medicate.

If you're experiencing symptoms of either a UTI or STI, it's advisable to see your healthcare professional in the first instance, for testing. The usual tests include:

  • Urine MCS tests (microscopy, culture and sensitivity analysis),
  • First pass urine (first of the urine flow) for Chlamydia trachomatis (CT) and Neisseria gonorrhoea (NG),
  • Molecular (PCR) tests of any lesion or discharge that can be swabbed which also includes low or high vaginal swabs and can be sent for CT, NG, Syphilis, Mycoplasma, Ureaplasma, HSV, Candida, Trichomonas and Lymphogranuloma venereum (LGV).

These are all very important and specific tests that should be done in order to establish the true cause of discomforting symptoms and order the appropriate treatment. Healthcare professionals are there to help you gain back your uro-genital health and advise you how to work on prevention of contracting potential STIs and UTIs.

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