Why blood tests look normal, but people still feel unwell?
"Your blood reports are normal."
For many people, this is where the confusion begins. Despite ongoing fatigue, poor digestion, brain fog, low mood, or reduced stamina, the tests show nothing clearly wrong. This disconnect can feel invalidating, but it is more common than most people realise.
Blood tests are designed to detect disease, not to measure how well the body is functioning day to day. Most laboratory "normal ranges" are statistical averages, not personalised targets. A value is considered normal if it falls within a range seen in the majority of the population, even if that level is not ideal for a particular individual.
This is why symptoms can appear before any marker becomes abnormal. Iron levels, for example, may fall within range but still be insufficient to support energy and oxygen delivery. Vitamin B12 may appear normal yet be inadequate for optimal neurological function. These are often referred to as functional or subclinical insufficiencies, states where the body is struggling, but not yet sick enough to be diagnosed.
Another limitation of blood tests is that they capture a snapshot in time. Human physiology is dynamic. Stress, poor sleep, under-eating, illness recovery, and hormonal shifts can all strain the body without immediately altering lab values. During this phase, the body compensates to maintain balance. People feel tired or uncomfortable not because something is "wrong," but because the system is under pressure.
The role of digestion and absorption
Digestion and absorption also play a crucial role. Blood tests assume that nutrients are being digested and absorbed efficiently. In reality, many individuals experience poor appetite, bloating, reflux, or irregular bowel habits, all of which affect nutrient availability. You can eat a nutritionally adequate diet and still absorb poorly, resulting in low-normal values that do not support vitality.
The impact of stress
Stress further complicates this picture. Chronic psychological stress alters digestion, appetite hormones, and glucose regulation. Research shows that stress can impair nutrient utilisation even when intake appears sufficient. This explains why people often feel worse during demanding periods, despite unchanged eating habits and "normal" test results.
Where nutrition makes a difference
This is where nutrition becomes especially important. Appropriate food interventions often improve energy, digestion, and mental clarity before any measurable change appears in lab reports. This does not mean blood tests are useless; they are essential for identifying disease. But they do not tell the whole story.
Health is not simply the absence of abnormal numbers. It is the presence of energy, comfort, and resilience. When symptoms persist despite normal reports, they deserve attention, not dismissal.
Nutrition, when used thoughtfully, often bridges the gap between "nothing is wrong" and actually feeling well.
