From Tolkien Gateway
The Dark Knife by Anke Eißmann

Morgul-wounds were inflicted by the weapons of Sauron's greatest servants — or, at least, by those of the Nazgûl. They carried dark enchantments that cursed the wounds suffered by their victims. The wounds themselves varied; those suffered by Steward Boromir in T.A. 2475 left him in crippling pain and shortened his life[1] (he died in 2489[2]), while the wound taken by Frodo on Weathertop[3] on 6 October 3018[4] threatened to make him a wraith.[5]

On 13 March 3019, when Faramir was retreating to Minas Tirith,[4] he held at bay a mounted soldier of Harad as the Nazgûl swirled overhead. Faramir was struck down by a flying dart - it was feared that it was from the Nazgûl and had created a Morgul-wound.[6] However, after the great battle Aragorn examined the wound and found it to be healing. This proved that Faramir had not suffered a Morgul-wound. It had been believed that it was such though due to Faramir's sickness and fever, but Aragorn diagnosed Faramir's condition as due to weariness, grief, wounding, and the Black Breath.[7]

See also