The pH Value stands for Potential Hydrogen (Sometimes, also called Percentage of Hydrogen). The pH Value of any solution is the measure of its Hydrogen-Ion and Hydroxide-Ion Concentration. Water molecule (H2O molecule breaks into a H+ ion and an OH– ion). The difference in the concentration of the Hydrogen ion and Hydroxide ions determine how Alkaline (Kshariye) or how Acidic (Amla) a Given Substance or the Given Fluid Is.
The Acidity/Alkalinity of a Substance may be found by using a pH Paper, which is made by Combination of Various Indicators (Available form a Chemical Shop). The pH Indicator (Paper) is made in such a way that it has a Reading from 0 to 14.
The Readings are such that a Reading of 7 Denotes that the Substance is Neutral. The Higher the pH Reading, the More Alkaline and Oxygen Rich the Substance is (due Presence of the Hydroxide Ion). The Readings of Greater Than 7 Right till the Value of 14 Denote the Substance to be Alkaline. The pH Value of 14 indicates the Extreme Alkaline Strength of the Substance.
The Lower The pH Value – Reading, the More Acidic and Oxygen Deprived the Fluid is. The pH Range from 0 to Less than 7 Indicates that the Substance is Acidic.
Just for academic reasons, pH of Human Blood is 7.4 (Which is Alkaline).
The above information is not a Medico-Legal advice. The information above is not intended to diagnose-treat-cure… any disease and you may use the above information at any/which way at your own risk and with own responsibility. Above is only my interpretation-understanding of the topic & is prone to errors.