The corpse of a deceased lord, afflicted with Crippling Decay.

"A horrible affliction indeed, Your Grace. But not to worry. The Crippled ones live mostly far north."
Grand Maester Pycelle
Crippling Decay, also known as The Highborn's Disease is a dreaded and usually fatal disease that can leave flesh and skin rotted and makes limbs fall off dead. Only a handful of people were ever able to survive the disease. The infection spreads until it has affected the entire body.

Strangely enough, only highborn people have ever been diagnosed with the disease, hence the nickname. Several kings and lords caught Crippling Decay and died young.

One of the very first known cases of Crippling Decay was King Aegon IV Targaryen. The maesters summoned to inspect him said they'd never seen anything like it before, and the septons declared it a "judgment of the Gods."

People afflicted with the disease are often called "Crippled ones", due to how their skin looks rotted and crippled.

Steffon Blackgard, the Black King of Ebonheart, has a rare form of Crippling Decay which has resulted in his physicality deteriorating slowly over a period of three months.

Signs and symptoms

A chronic illness, Crippling Decay is primarily a granulomatous disease of the peripheral nerves and mucosa of the upper respiratory tract; skin lesions (light or dark patches) are the primary external sign. If untreated, Crippling Decay can progress and cause permanent damage to the skin, nerves, limbs, and eyes. Contrary to folklore, Crippling Decay does not cause body parts to fall off, although they can become numb or diseased as a result of secondary infections; these occur as a result of the body's defences being compromised by the primary disease. Secondary infections, in turn, can result in tissue loss, causing fingers and toes to become shortened and deformed, as cartilage is absorbed into the body.

The development of the Crippling Decay virus starts early on, mostly around infancy. One of the starting symptoms and signs of Crippling Decay starts with pneumonia, asthma, or sometimes cystic fibrosis. Although no physical signs can be seen, the respiratory symptoms will start to disappear through the years. It is universally agreed by the maesters of the Citadel that any real physical deterioration starts when the patient is around 20 – 35 years old.

As the disease progresses, one's ability to speak, swallow, and walk will become more difficult, resulting in the patient having to use canes or even wheelchairs to move around. Around the ending stages of Crippling Decay, a patient may be required an interpreter to translate one's failing speech.

Although in most cases Crippling Decay is caught during infancy and is typically hereditary, this is not always the case. Since it's a virus, Crippling Decay can be caught by any healthy person later in life. The usual transmitters of the disease are rodents and infected water.

Season 4

Ralf Kenning, an ironborn raider at Moat Cailin has Crippling Decay in its early stages.