Symptoms of Common STIs: A Clinical Visual Guide to Identification

Sexually transmitted infections (STIs) are common, and many are treatable—especially when identified early. Understanding STI symptoms can help you recognize when something may be wrong and prompt timely care. This guide uses clear, plain language and clinically accurate descriptions to help you understand what different STIs may look and feel like. While visuals can be helpful, symptoms can vary widely by person, anatomy, and stage of infection. If anything here feels familiar or concerning, it's important to speak to a doctor—especially if symptoms are severe, persistent, or could be life-threatening.

Important note: Some STIs cause no symptoms at all. Regular screening is essential if you're sexually active.

---

How to Use This Visual Guide

Think of this as a checklist of common signs and sensations rather than a diagnostic tool. Many conditions can look similar, and only a medical test can confirm an STI.

---

Chlamydia

Overview: Chlamydia is one of the most common bacterial STIs and is often silent.

Common STI symptoms may include:

• Unusual vaginal or penile discharge (often clear or cloudy)
• Burning or pain during urination
• Pelvic or lower abdominal pain
• Pain during sex
• Testicular pain or swelling (less common)
• Rectal pain, discharge, or bleeding (with anal exposure)

Visual clues:
Discharge may be subtle. In people with vaginas, the cervix may appear inflamed during an exam.

Why it matters: Untreated chlamydia can lead to pelvic inflammatory disease (PID) and fertility problems.

---

Gonorrhea

Overview: Gonorrhea often occurs alongside chlamydia and may cause more noticeable symptoms.

Common STI symptoms may include:

• Thick, yellow or green discharge from the penis or vagina
• Pain or burning during urination
• Increased vaginal bleeding between periods
• Testicular pain or swelling
• Rectal discomfort, discharge, or bleeding
• Sore throat (with oral exposure)

Visual clues:
Discharge is often more pronounced and may stain underwear.

Why it matters: Untreated gonorrhea can cause joint infections, PID, and infertility.

---

Syphilis

Overview: Syphilis develops in stages, each with different symptoms.

Stage 1 (Primary):

• A single, firm, painless sore (chancre) at the site of infection
• Swollen lymph nodes

Stage 2 (Secondary):

• Rash (often on palms of hands or soles of feet)
• Fever, fatigue, sore throat
• Patchy hair loss
• Flat, wart-like growths in the genital area

Later stages:

• Damage to the brain, nerves, heart, or other organs

Visual clues:
The initial sore can be easy to miss because it doesn't hurt.

Why it matters: Syphilis can be life-threatening if untreated. Early treatment is very effective.

---

Genital Herpes (HSV-1 and HSV-2)

Overview: Herpes is a viral STI that remains in the body for life, with periods of flare-ups.

Common STI symptoms may include:

• Tingling or itching before sores appear
• Small blisters that break open into painful ulcers
• Pain during urination
• Flu-like symptoms during the first outbreak

Visual clues:
Clusters of fluid-filled blisters or open sores around the genitals, anus, or mouth.

Why it matters: While not curable, herpes is manageable with antiviral medication.

---

Human Papillomavirus (HPV)

Overview: HPV is extremely common. Many types cause no symptoms and clear on their own.

Common STI symptoms may include:

• Genital warts (soft, flesh-colored bumps; flat or cauliflower-like)
• Often no symptoms at all

Visual clues:
Warts may appear weeks or months after exposure and can be very small.

Why it matters: Some HPV types can lead to cervical, anal, throat, or penile cancers. Regular screening is key.

---

Trichomoniasis

Overview: A parasitic STI that is more common than many realize.

Common STI symptoms may include:

• Frothy, yellow-green vaginal discharge
• Strong vaginal odor
• Vaginal itching or irritation
• Pain during urination or sex
• Penile irritation or discharge (often mild or absent)

Visual clues:
In clinical exams, the cervix may appear red or inflamed.

Why it matters: It increases the risk of acquiring or transmitting other STIs.

---

HIV (Human Immunodeficiency Virus)

Overview: HIV affects the immune system and may not cause symptoms for years.

Early symptoms (2–4 weeks after exposure):

• Fever
• Sore throat
• Rash
• Swollen lymph nodes
• Fatigue

Later symptoms (if untreated):

• Recurrent infections
• Weight loss
• Night sweats

Visual clues:
Early rashes are often flat and widespread, not itchy.

Why it matters: Early diagnosis and treatment allow people with HIV to live long, healthy lives.

---

When Symptoms Overlap or Are Absent

Many STI symptoms look alike—or don't appear at all. Discharge, sores, itching, and pain can also be caused by non-STI conditions such as yeast infections or skin irritation. That's why testing matters more than visual inspection alone.

---

Emotional and Psychological Considerations

Experiencing genital symptoms can be stressful. If your symptoms follow an unwanted sexual experience, you may also notice emotional signs such as anxiety, sleep problems, or avoidance. Understanding what you're feeling is an important part of healing—consider using a free Sexual Trauma symptom checker to help identify both physical and emotional symptoms and learn about support options available to you.

---

When to Speak to a Doctor Immediately

You should speak to a doctor or seek urgent care if you experience:

• Severe pelvic or abdominal pain
• High fever
• Rapidly spreading rash
• Neurological symptoms (vision changes, weakness, confusion)
• Painful swelling of the testicles
• Any symptom that feels sudden, severe, or life-threatening

---

Key Takeaways

• STI symptoms vary widely and may be mild, severe, or absent.
• Visual signs can guide concern but cannot confirm a diagnosis.
• Early testing and treatment protect your health and your partners.
• Most STIs are treatable, and many are curable.
• If something feels off, trust that instinct and speak to a doctor.

Understanding your body is an important step toward staying healthy. If you're unsure, uncomfortable, or worried about what you're noticing, medical professionals are trained to help—without judgment and with your safety in mind.