How Blood Type Influences Your Level Of Stress And Fatigue

Everyone gets tired sometimes, but fatigue is much more than that. Many different things can cause fatigue; among them are immune system malfunction, stress, and toxicity.

The immune system destroys harmful things like bacteria and viruses while protecting its own cells. Chemicals called antigens are often found on the surface of cells, and the body uses these to help tell the cells apart.


Normally, the body creates antibodies to foreign cells. Auto-immune diseases occur when the body gets confused and treats its own cells like invaders.

Red blood cells have antigens, and these vary by blood type.

  • People with O blood create antibodies to the A and B antigens,
  • As create B antibodies,
  • Bs create A antibodies, and
  • ABs don’t create basic blood type antibodies at all, since they have the A and the B antigen on their cells.

Blood Type And The Health Conditions

  • Type Os – Because Os have more natural antibodies than other types, the immune system is “primed” to react to more things. They are more likely to get auto-immune conditions.
  • Type As – They are most vulnerable to immune system depletion, getting sick more often.
  • Type Bs – They are more prone to viral infections, including slow-growing ones that lead to autoimmune conditions. They’re most susceptible to influenza and urinary tract infections.
  • Type ABs – They have the weaknesses of As and Bs.

Response To Stress

Our bodies are designed to handle short bursts of stress, but chronic stress can cause health problems and fatigue. Our stress response system has two basic parts; one to put the body into “stress mode” and the other to return the body to rest. The time at rest is important for proper digestion, healing, and normal cell repair.

Adrenaline is designed for short-term stress response, while cortisol is used for the medium-term.

  • Type Os tend to secrete higher levels of adrenaline in response to stress, but have a harder time clearing it  away later. Exercise helps the type O body “burn off” the extra adrenaline, restoring calm to the body.
  • Type ABs also produce high levels of adrenaline.
  • Type As have higher levels of cortisol all the time. Type As need to focus on calming exercises, minimizing the cortisol spike in the first place.
  • Type Bs produce high amounts of cortisol in response to stress. Type Bs respond well to meditation and visualization.

Sustained high cortisol levels destroy healthy muscle and bone, slows down healing, impairs digestion, metabolism, and mental function. Producing all that cortisol also uses up the building blocks for other hormones, leading to various endocrine problems.

Fatigue: What Happens Inside The Body

Cells create energy from oxygen and food, storing it as ATP (Adenosine Triphosphate). Molecules called second messengers tell the cells when to release ATP. Stress hormones cause more of these messengers to be active, calling for more ATP to be released at once.


When the cells keep being told to release energy faster than they can make it, they stop responding as well. This leads to less energy being released from cells at all times. Less cellular energy means more fatigue.

Normal metabolism produces cellular wastes, called endotoxins. Xenobiotics are foreign substances found inside the body, such as chemicals that are breathed in, or pesticide residues from foods. Dietary lectins can affect your body’s ability to clear both natural and foreign toxins from the body, and this toxic buildup can lead to fatigue.


Lectins are natural proteins found in foods that react with blood type antigens. Since there are blood type antigens found in the digestive tract, dietary lectins can cause inflammation in the gut and affect digestion.

Sluggish digestion can cause fatigue as less energy is drawn from food. Some lectins make it into the blood stream to cause problems elsewhere in the body.  Lectins are very blood type specific; there are foods that are toxic for one blood type yet perfectly healthy for another.


Following the Blood Type Diet and Exercise recommendations can relieve fatigue. You’ll be cutting out harmful lectins that make your body less efficient, as well as foods you can’t digest properly.

Exercise Just Right

Learning how to exercise “just right” is important too.


Over-exercising will cause cortisol levels to spike in As, increasing stress rather than relieving it. Meanwhile, Type Os  tend to thrive on vigorous aerobic exercise, and Bs and ABs fall somewhere in between.

Those coping with chronic fatigue need to start slowly and avoid over exertion, regardless of blood type.