Common mathematical signs, symbols, statistical and medical terms
Table: mathematical signs and symbols
| + | plus |
| − | minus |
| ÷ | divided by |
| × | multiplied by (‘times’) |
| = | equals |
| ≠ | not equal to |
| > | greater than (ie >500 means ‘more than 500’) |
| ≥ | greater than or equal to (ie ≥500 means ‘500 and over’) |
| < | less than |
| ≤ | less than or equal to |
| ~ | approximately |
| ± | plus or minus – this is use to show the range of group of values (Standard Deviation) when the mean is used to calculate the average, eg SD ± 0.45. |
| % | percentage |
| n | number (in a statistical sample, eg n=16 means 16 results, people etc) |
Table: Greek characters
| α | alpha or alfa | a |
| β | beta | b |
| Δ δ | delta | d – this is the abbreviation for ‘change |
| γ | gamma | g |
| μ | mu | m – this is the abbreviation for ‘micro’ eg µL = micro litre |
Greek letter are commonly used for names of immune-related chemicals, ie interferon-alpha (IFN-a, IFN-α) or interferon-beta (INF-b, IFN-β) to treat hepatitis C.
Delta is used as a short cut for ‘change’, ie delta CD4 (ΔCD4 or δCD4) means ‘change in CD4’.
Table: medical abbreviations
| qd or QD | once daily |
| bd or BD or BID | twice daily |
| td or TD or TID | three times daily |
| q12h or q12H | every 12 hours |
| q24h or q24H | every 24 hours |
| Bx | biopsy |
| Dx | diagnosis, diagnosed |
| Px | problem, symptom (P = patient) |
| Rx | prescription or resistance |
| Tx | treatment |
Last updated: 22 July 2009.