His father was a dock worker in Leith until bad health forced him to stop, after which he became a carpet salesman; he died when Welsh was 25.

A series of arrests for petty crimes and finally a suspended sentence for trashing a North London community centre inspired Welsh to correct his ways.

Set in the mid-1980s, it uses a series of non-linear and loosely connected short-stories to tell the story of a group of characters tied together by decaying friendships, heroin addiction and stabs at escape from the oppressive boredom and brutality of their lives in the social housing schemes.

Many of the stories take place in and around the housing schemes from Trainspotting, and employ many of the same themes; a touch of fantasy is apparent in stories such as The Acid House, where the minds of a baby and a drug user swap bodies, or The Granton Star Cause, where God transforms a man into a fly[4] as punishment for wasting his life.

His next book, Ecstasy: Three Tales of Chemical Romance (1996), became his most high-profile work since Trainspotting, released in the wave of publicity surrounding the film.

It consists of three unconnected novellas: the first, Lorraine Goes To Livingston, is a bawdy satire of classic British romance novels, the second, Fortune's Always Hiding, is a revenge story involving thalidomide and the third, The Undefeated, is a sly, subtle romance between a young woman dissatisfied with the confines of her suburban life and an aging clubgoer.

Glue (2001) was a return to the locations, themes and episodic form of Trainspotting, telling the stories of four characters spanning several decades in their lives and the bonds that held them together.

[4] The Bedroom Secrets of the Master Chefs (2006), deals with a young, alcoholic civil servant who finds himself inadvertently putting a curse on his nemesis, a nerdy co-worker.

In Crime, Ray Lennox (from Welsh's previous work, Filth) is recovering from a mental breakdown induced by occupational stress and cocaine abuse, and a particularly horrifying child sex murder case back in Edinburgh.

Welsh's tenth novel, released in April 2016, The Blade Artist, centres around a seemingly rehabilitated Francis Begbie now living in California with a wife and children.

[9] A sequel to The Blade Artist, entitled Dead Men's Trousers, was released on 29 March 2018, and sees Mark Renton, Sick Boy, and Spud reuniting with Francis Begbie.

In 2021, a TV adaptation of Crime was launched in the UK on BritBox as a six-episode series starring Dougray Scott as detective Lennox.

As well as fiction, Irvine Welsh has written several stage plays, including Headstate, You'll Have Had Your Hole, and the musical Blackpool, which featured original songs by Vic Godard of the Subway Sect.

Despite the historical source material, Welsh has set the story in the familiar confines of present-day Edinburgh, with Burke and Hare depicted as brothers who steal human organs to meet the demands of the global transplant market.

The film centres around the lives of four young women, who are played by Michelle Gomez, Shirley Henderson, Shauna MacDonald, and Kathleen McDermot.

The film features Joe McKinney as a man dealing with testicular cancer in post Celtic tiger Ireland.

[11] As well as recreational drug use, Welsh's fiction and non-fiction is dominated by the question of working class and Scottish identity in the period spanning the 1960s to the present day.

Within this, he explores the rise and fall of the council housing scheme, denial of opportunity, low-paid work, unemployment, social assistance, sectarianism, football, hooliganism, sex, suppressed homosexuality, dance clubs, freemasonry, Irish republicanism, sodomy, class divisions, emigration and, perhaps most of all, the humour, prejudices and axioms of the Scots.

Sam Leith, writing in the Financial Times, argues that: "Welsh's concerns are with sin and salvation, with the exercise of free will and with the individual soul.