HD
Abbreviation with 8 meanings
| Stands for | High definition |
|---|---|
| Meanings | 8 |
| Categories | Technology & Computing, Medical |
HD has eight meanings. The most common are High definition (consumer electronics) and Hemodialysis (nephrology & urology); it can also stand for Huntington's disease, Hazardous drug, Hodgkin disease, Hospital day and Hard disk, plus 1 more listed below.
Meanings of HD at a glance
| # | HD stands for | Context |
|---|---|---|
| 1 | High definition | Technology & Computing › Consumer Electronics |
| 2 | Hemodialysis | Medical › Nephrology & Urology |
| 3 | Huntington's disease | Medical › Neurology |
| 4 | Hazardous drug | Medical › Pharmacy |
| 5 | Hodgkin disease | Medical › Hematology and Oncology |
| 6 | Hospital day | Medical › Medical Documentation |
| 7 | Hard disk | Technology & Computing › Computer Hardware |
| 8 | Hierarchical deterministic (wallet) | Technology & Computing › Cryptocurrency & Blockchain |
1. High definition
Technology & Computing · Consumer Electronics Abbreviations
Video or display resolution higher than standard definition, most often meaning 1280 by 720 (720p) or 1920 by 1080 (1080p, "Full HD"). The label appears on TVs, streaming plans, cameras, phone screens and broadcast channels.
Example: The basic streaming plan only plays in HD, not 4K.
Usage is loose: European "HD ready" labels from 2005 guaranteed only 720p capability, while "Full HD" meant 1080p. Phone makers use "HD+" for screens around 720 pixels wide. Streaming services may label 720p as HD and 1080p as Full HD. In voice calls, "HD Voice" refers to wideband audio, an unrelated use of the term.
2. Hemodialysis
Medical · Nephrology & Urology Abbreviations
Treatment that filters blood through an external dialyzer to remove waste and fluid when the kidneys fail. Most patients attend a dialysis center three times a week for sessions of roughly 3–5 hours, using an arteriovenous fistula, graft or catheter for access.
Example: ESRD on HD Tuesday-Thursday-Saturday; missed session, potassium 6.4, arrange urgent dialysis.
Willem Kolff built the first practical artificial kidney in the Netherlands in 1943. Home hemodialysis, nocturnal sessions and more frequent short treatments are alternatives to the standard schedule. Adequacy is measured by Kt/V or the urea reduction ratio. In neurology HD can instead mean Huntington's disease.
3. Huntington's disease
Medical · Neurology Abbreviations
Inherited neurodegenerative disease caused by an expanded CAG repeat in the HTT gene, producing involuntary movements (chorea), psychiatric symptoms and progressive cognitive decline, usually starting between ages 30 and 50. Each child of an affected parent has a 50 percent chance of inheriting it.
Example: Mother died of HD; patient with chorea and irritability, CAG repeat 44 confirmed on genetic testing.
Described by American physician George Huntington in 1872, and the gene was identified in 1993. Forty or more CAG repeats cause the disease with full penetrance, while 36 to 39 show reduced penetrance. Drugs such as tetrabenazine, deutetrabenazine and valbenazine reduce chorea but do not slow progression. Folk singer Woody Guthrie died of HD. In nephrology HD means hemodialysis.
4. Hazardous drug
Medical · Pharmacy Abbreviations
Medicine that poses a risk to healthcare workers through occupational exposure because it can cause cancer, birth defects, reproductive harm or organ toxicity at low doses. Chemotherapy agents, some hormones and drugs such as methotrexate and valganciclovir are classed as HDs.
Example: HD precautions: double chemo gloves and a gown when crushing tamoxifen.
NIOSH maintains the US list of hazardous drugs, and USP chapter 800 sets handling requirements for receiving, storing, compounding, administering and disposing of them. HD labels and yellow chemo waste bins are common signals. In nephrology HD means hemodialysis, a much more frequent meaning.
5. Hodgkin disease
Medical · Hematology and Oncology Abbreviations
Older name for Hodgkin lymphoma, used before the disease was firmly established as a cancer of B lymphocytes. It persists in older medical records, survivor histories and some lay sources.
Example: Remote history of HD treated with mantle radiation in 1984; screening for radiation-related breast cancer and heart disease.
The World Health Organization classification of 2001 formally adopted "Hodgkin lymphoma." Many long-term survivors treated in the 1970s and 1980s with extended-field radiation need lifelong screening for secondary breast and thyroid cancers and early coronary and valve disease. In nephrology HD means hemodialysis, and in neurology Huntington's disease.
6. Hospital day
Medical · Medical Documentation Abbreviations
Count of days since admission, used in progress notes and handoffs, as in "HD 4". It helps readers track the course and timing of treatments.
Example: HD 5: afebrile, cultures negative, plan transition to oral antibiotics.
Admission day is usually HD 0 or HD 1 depending on local convention, so mixing styles can cause off-by-one confusion. Surgical patients are tracked by postoperative day (POD) instead. In nephrology HD means hemodialysis, a much more common use of the letters.
7. Hard disk
Technology & Computing · Computer Hardware Abbreviations
Older shorthand for a hard disk or hard drive, still seen in the default name of a Mac's startup volume, "Macintosh HD", and in some device menus and manuals.
Example: Open Macintosh HD in Finder to see the Applications and Users folders.
In 1980s and 1990s computer ads, "HD" or "HDD" listed the hard disk capacity, as in "40 MB HD". On floppy disks, the HD label meant high density, marking 1.44 MB 3.5-inch disks, while DD meant double density. In television and video, HD almost always means high definition.
8. Hierarchical deterministic (wallet)
Technology & Computing · Cryptocurrency & Blockchain Abbreviations
A wallet design in which every key and address is derived from a single seed, usually backed up as a 12- or 24-word recovery phrase, so restoring that phrase recovers every account. Nearly all modern crypto wallets work this way.
Example: Because it's an HD wallet, writing down the seed phrase backs up every address it will ever create.
Defined in Bitcoin Improvement Proposal 32 (2012), with BIP 39 standardizing mnemonic phrases and BIP 44 a path structure for multiple coins and accounts. Anyone who obtains the seed phrase controls all the funds, so it must never be typed into websites. In consumer electronics HD means high definition.
Related abbreviations
More consumer electronics abbreviations
- FHD – Full High Definition
- FOV – Field of view
- FPS – Frames per second
- GaN – Gallium nitride
- HDCP – High-bandwidth Digital Content Protection
- HDR – High dynamic range
- HDR10 – High Dynamic Range 10
- HDTV – High-definition television
See all 104 consumer electronics abbreviations →
More nephrology & urology abbreviations
- FENa – Fractional excretion of sodium
- FSGS – Focal segmental glomerulosclerosis
- GN – Glomerulonephritis
- GU – Genitourinary
- HoLEP – Holmium laser enucleation of the prostate
- HUS – Hemolytic uremic syndrome
- IC – Interstitial cystitis
- IgAN – IgA nephropathy
See all 71 nephrology & urology abbreviations →
This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.