pH
Abbreviation with 7 meanings
| Stands for | Potential of hydrogen |
|---|---|
| Meanings | 7 |
| Categories | Science & Engineering, Geography & Places, Medical, Sports |
| Also written | PH, Ph |
pH has seven meanings. The most common are Potential of hydrogen (chemistry) and Philippines (country code); it can also stand for Philadelphia chromosome, Pulmonary hypertension, Penthouse, Phenyl group and Pinch hitter.
Meanings of pH at a glance
| # | pH stands for | Context |
|---|---|---|
| 1 | Potential of hydrogen | Science & Engineering › Chemistry |
| 2 | Philippines | Geography & Places › Country Code |
| 3 | Philadelphia chromosome | Medical › Hematology and Oncology |
| 4 | Pulmonary hypertension | Medical › Respiratory |
| 5 | Penthouse | Geography & Places › Address |
| 6 | Phenyl group | Science & Engineering › Chemistry |
| 7 | Pinch hitter | Sports › Baseball |
1. Potential of hydrogen
Science & Engineering · Chemistry Abbreviations
Scale from about 0 to 14 that expresses how acidic or basic a water solution is, defined as the negative logarithm of hydrogen-ion activity. Pure water at 25 °C is neutral at pH 7; lemon juice is around 2, blood about 7.4 and household bleach about 12-13. Each unit is a tenfold change.
Example: Adjust the buffer to pH 7.4 with 1 M sodium hydroxide before filtering.
Danish chemist Søren Sørensen introduced the concept in 1909 at the Carlsberg Laboratory. What the "p" originally stood for is debated, with suggestions including German Potenz and French puissance (power); in modern notation p simply means "negative logarithm of," as in pKa. It is always written pH, never PH or Ph (Ph is the phenyl group).
2. Philippines (PH)
Geography & Places · Country Code Abbreviations
The Philippines, an archipelago of about 7,600 islands with Manila as its capital and PHL as its alpha-3 code, is widely called PH online and in local media. Its peso trades as PHP, the same letters as the PHP programming language.
Example: Remote workers in PH make up a large share of the global call-center industry.
In chemistry pH measures acidity. The Filipino and English languages are both official. The country is named after King Philip II of Spain.
3. Philadelphia chromosome (Ph)
Medical · Hematology and Oncology Abbreviations
Shortened chromosome 22 created by a swap of genetic material between chromosomes 9 and 22, t(9;22), which forms the BCR-ABL1 fusion gene. It is found in about 95 percent of chronic myeloid leukemia and in a subset of acute lymphoblastic leukemia.
Example: Cytogenetics: 46,XY,t(9;22) in 20 of 20 metaphases; Ph-positive CML.
Discovered in 1960 by Peter Nowell and David Hungerford in Philadelphia, it was the first chromosomal abnormality consistently linked to a cancer. Ph-positive ALL is treated with tyrosine kinase inhibitors alongside chemotherapy or immunotherapy. In respiratory medicine PH means pulmonary hypertension, and pH denotes acidity.
4. Pulmonary hypertension (PH)
Medical · Respiratory Abbreviations
Raised blood pressure in the pulmonary arteries, defined since 2022 by a mean pulmonary artery pressure above 20 mmHg at rest on right heart catheterization. It strains the right ventricle and causes breathlessness, fatigue, fainting and leg swelling.
Example: Echo RVSP 70 with RV dilation; RHC confirms PH with mPAP 42 and wedge 24, group 2 from HFpEF.
The WHO classifies PH into five groups: pulmonary arterial hypertension (group 1), left heart disease (group 2, the most common), lung disease or hypoxia (group 3), chronic thromboembolic and other pulmonary artery obstructions (group 4), and unclear or multifactorial causes (group 5). Treatment depends on the group. The same letters written pH denote acidity, a measurement reported in every blood gas.
5. Penthouse (PH)
Geography & Places · Address Abbreviations
Unit designator for a penthouse apartment on the top floor of a building, as in 200 Park Ave PH 2. Elevator panels often label the top floor PH.
Example: The listing for 30 River Rd PH 3 sold for a record price.
PH is the USPS standard. The same letters mean pH, the acidity scale, and PH, the ISO code for the Philippines.
6. Phenyl group (Ph)
Science & Engineering · Chemistry Abbreviations
Abbreviation for the phenyl group, -C6H5, a benzene ring attached to the rest of a molecule through one of its carbons. It appears in formulas and names such as PhOH (phenol), PhMe (toluene) and PPh3 (triphenylphosphine).
Example: The Wittig reagent was prepared from PPh3 and benzyl bromide.
Written with a capital P and lowercase h; it should not be confused with pH, the acidity scale. Related abbreviations include Ar for a generic aryl group and Bn for benzyl (C6H5CH2-). The letters Ph in the degree Ph.D. are unrelated.
7. Pinch hitter (PH)
Sports · Baseball Abbreviations
Substitute batter who hits in place of another player in the lineup, often in a key late-game situation. The replaced player cannot return to the game.
Example: The manager sent up a PH with two outs and the tying run on second.
The universal designated hitter reduced pinch-hitting for pitchers. Lenny Harris holds the career record for pinch hits. In chemistry pH measures acidity, written with a lowercase p.
Related abbreviations
More chemistry abbreviations
- PET – Polyethylene terephthalate
- PFAS – Per- and polyfluoroalkyl substances
- PFOA – Perfluorooctanoic acid
- PFOS – Perfluorooctanesulfonic acid
- pKa – Acid dissociation constant (negative logarithm)
- PLA – Polylactic acid
- PMMA – Poly(methyl methacrylate)
- PP – Polypropylene
See all 106 chemistry abbreviations →
More country code abbreviations
- PAR – Paraguay
- PE – Peru
- PF – French Polynesia
- PG – Papua New Guinea
- PK – Pakistan
- PL – Poland
- PM – Saint Pierre and Miquelon
- PN – Pitcairn Islands
See all 270 country code abbreviations →
This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.