Does Being O Positive Mean Mosquitoes Bite Me More Than Other People?

If you have an o positive blood type, you may have heard that mosquitoes are more attracted to you than to others. While blood type does play a role in mosquito preference, it’s only one factor among many. Here’s what the research really says—and what you can do about mosquito bites.

How Mosquitoes Choose Their Targets

Mosquitoes use a combination of cues to find a blood meal:

• Carbon dioxide: All humans exhale CO₂, but some people emit more due to higher metabolism or larger body size.
• Body heat: Mosquitoes sense infrared radiation and home in on warmer skin areas.
• Skin odors: Skin bacteria break down sweat into compounds like lactic acid, ammonia and carboxylic acids that attract mosquitoes.
• Visual cues: Dark clothing and movement can make you more noticeable.
• Blood type: Certain blood groups may give off chemical markers in sweat that mosquitoes detect.

No single cue operates in isolation. The combined effect of these signals determines how often a mosquito lands on you.

What Research Says About Blood Type O Positive

Several peer-reviewed studies have examined how blood type influences mosquito biting behavior:

• A study published in the Journal of Medical Entomology found that mosquitoes landed on people with O blood type nearly twice as often as those with A blood type.
• Research suggests that if you have a blood group O (including o positive blood type), your skin may exude certain compounds at higher levels, making you more attractive to some mosquito species.
• However, the difference in attractiveness based solely on blood group is generally modest—mosquitoes still rely heavily on CO₂, body heat and skin odors.

Key takeaway: Yes, o positive blood type can make you a slightly more appealing target for mosquitoes, but it’s just one element in a complex mix of attractants.

Other Factors That Matter More Than Blood Type

Even if you have an o positive blood type, other factors can have a greater impact on how often mosquitoes bite you:

• Metabolism and activity level
  Higher exertion produces more CO₂ and heat, making you a bigger target during exercise or warm-weather activities.

• Skin microbiome
  The types and densities of bacteria on your skin influence the profile of odors you emit—this can be a stronger attractant than blood group alone.

• Body temperature and sweat
  Those who run hotter or sweat more heavily tend to draw more mosquitoes.

• Clothing color
  Dark colors (black, navy, red) stand out more to mosquitoes than pastels or whites.

• Pregnancy
  Pregnant people exhale more CO₂ and often run warmer, increasing bite risk.

In many cases, these factors outweigh the effect of having an o positive blood type.

Practical Tips to Reduce Mosquito Bites

Regardless of your blood group, you can take steps to lower your bite count:

1. Use EPA-registered repellents
   Look for ingredients like DEET, picaridin or oil of lemon eucalyptus.

2. Wear protective clothing
   Long sleeves, pants and light colors make it harder for mosquitoes to land.

3. Install screens and nets
   Window screens, bed nets and outdoor fans disrupt mosquito flight.

4. Remove standing water
   Empty birdbaths, clogged gutters and puddles where mosquitoes breed.

5. Shower after exercise
   Rinsing off sweat reduces odor cues that attract mosquitoes.

6. Use natural deterrents
   Citronella candles, mosquito-repellent plants (lemongrass, catnip) and essential oils can offer extra protection outdoors.

When to Seek Professional Advice

Most mosquito bites are an itchy nuisance rather than a serious health risk. However, if you notice:

• Signs of infection (increased redness, swelling, warmth or pus)
• Fever, body aches or rash within two weeks of a bite
• Severe allergic reactions (hives, difficulty breathing)

…you should speak to a doctor right away. For a quick, free, online symptom check, using the doctor approved Ubie Symptom Checker, click here.

Bottom Line

Having an o positive blood type may make you marginally more attractive to mosquitoes than someone with a different blood group. But factors like how much you sweat, your body heat, the bacteria living on your skin and even the color of your clothing often play a far bigger role. By combining proven bite-prevention strategies—repellents, protective clothing and habitat reduction—you can stay more comfortable outdoors, no matter your blood type.

Always pay attention to your body’s signals. If you experience severe reactions or concerning symptoms after mosquito exposure, please speak to a doctor to rule out any serious issues.