ALT
Abbreviation with 4 meanings
| Stands for | Alanine aminotransferase |
|---|---|
| Meanings | 4 |
| Categories | Medical, Technology & Computing, Texting & Internet Slang |
| Also written | Alt |
ALT has four meanings. The most common are Alanine aminotransferase (laboratory test) and Alternate key (computer); it can also stand for Alternate account and Alternate character.
Meanings of ALT at a glance
| # | ALT stands for | Context |
|---|---|---|
| 1 | Alanine aminotransferase | Medical › Laboratory Test |
| 2 | Alternate key | Technology & Computing › Computer |
| 3 | Alternate account | Texting & Internet Slang › Social Media |
| 4 | Alternate character | Texting & Internet Slang › Gaming Slang |
1. Alanine aminotransferase
Medical · Laboratory Test Abbreviations
The most liver-specific routine enzyme, released when liver cells are injured by viral hepatitis, fatty liver disease, alcohol, medications or reduced blood flow. Many labs use upper limits around 40 to 56 U/L, though the American College of Gastroenterology suggests healthy values are closer to 33 U/L in men and 25 U/L in women.
Example: ALT 62 on two checks; ultrasound shows steatosis, consistent with MASLD.
Formerly called SGPT. Values above about 1,000 U/L narrow the cause to acute viral hepatitis, ischemic hepatitis (shock liver), acetaminophen toxicity or acute bile duct obstruction. Mildly raised ALT in an otherwise well adult is most often due to fatty liver. ALT is often checked before and during treatment with drugs such as isoniazid, methotrexate and some antifungals.
2. Alternate key (Alt)
Technology & Computing · Computer Abbreviations
Modifier key beside the space bar on PC keyboards, used in shortcuts such as Alt+Tab to switch windows and Alt+F4 to close one. Holding it while typing a number on the numeric keypad inserts special characters in Windows.
Example: Hold Alt and type 0151 on the numeric keypad to insert an em dash.
On Mac keyboards the corresponding key is labeled Option, and many also print "alt" on it. Pressing Alt alone in many Windows programs highlights the menu bar or reveals ribbon shortcuts. The right-hand Alt key on international layouts is usually AltGr, which types extra characters instead of acting as a shortcut modifier.
3. Alternate account (Alt)
Texting & Internet Slang · Social Media Abbreviations
Second social media account used for a different purpose or audience, such as a private account for close friends, a fan account, a meme page or an anonymous profile. Common on Instagram, X, TikTok and Reddit.
Example: Posting this on my alt because my coworkers follow my main.
Instagram "finstas" (fake Instagrams) shared only with close friends are a well-known type of alt. Alts can be harmless, but they are also used to evade bans or harass people, which most platforms prohibit. In gaming, an alt is a secondary character on the same account.
4. Alternate character (Alt)
Texting & Internet Slang · Gaming Slang Abbreviations
Secondary character a player creates on the same account or server, distinct from their "main." Used to try other classes, store items or play with different friends.
Example: Leveling my healer alt so I can fill in when the raid needs one.
Common in MMORPGs such as World of Warcraft and Final Fantasy XIV, where many players keep several alts. "Altoholic" describes someone who constantly makes new characters. On social media an alt is a secondary account, a related but separate sense.
Related abbreviations
More laboratory test abbreviations
- AG – Anion gap
- Alb – Albumin
- ALC – Absolute lymphocyte count
- ALP – Alkaline phosphatase
- ANA – Antinuclear antibody
- ANC – Absolute neutrophil count
- anti-CCP – Anti-cyclic citrullinated peptide antibody
- Anti-Xa – Anti-factor Xa assay
See all 135 laboratory test abbreviations →
More computer abbreviations
- ACPI – Advanced Configuration and Power Interface
- AD – Active Directory
- AltGr – Alternate Graphic key
- APFS – Apple File System
- ASCII – American Standard Code for Information Interchange
- BIOS – Basic Input/Output System
- BOM – Byte order mark
- BSOD – Blue Screen of Death
See all 92 computer abbreviations →
This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.