Phase 1 · Understand the Body — Why the disease behaves the way it does.
The One-Line Truth
The whole disease in one chain
Everything on this page exists to explain this line.
Blood pH drops below 7.35 because the body either makes too much acid or loses too much bicarbonate—the main buffer that neutralizes acid.
Your blood's pH is a thermostat that keeps breaking
Imagine your blood is a house and pH is the temperature set to 72°F (7.35–7.45). Metabolic acidosis (acid building up in the blood) is like three different ways the thermostat breaks and the house gets too cold. First, the furnace (your cells) might overproduce heat (lactic acid from shock) or switch to burning dirty fuel (ketones from starvation), flooding the house with acid. Second, the air filter (your kidneys) might jam and stop cleaning out acidic ash, or the drain (your gut) might leak all the buffering soda you use to neutralize the acid. Third, someone might have poured salt water (normal saline) through the heating system, diluting out all the buffer that was working. Meanwhile, your body's only fast fix is to open all the windows and blast a fan (hyperventilate) to blow out CO₂, but you can't fan forever—eventually someone collapses from exhaustion and the house freezes. The deeper problem—broken furnace, clogged filter, leaky drain, or diluted buffer—must be fixed by treating the root cause, not just fanning harder.
NEJM: Berend et al. Physiological Approach to Acid-Base Disturbances, 2014 · NEJM: Seifter. Integration of Acid-Base and Electrolyte Disorders, 2014 · ADA Standards of Care in Diabetes 2025 (Hyperglycemic Crises) · NEJM: Kraut & Madias. Lactic Acidosis, 2014 · reviewed 2026-07-07