What might happen to a limb affected by compartment syndrome if left untreated?

In the case of untreated compartment syndrome, the buildup of pressure within a muscle compartment can lead to a severe reduction in blood flow to the affected tissues. This ischemia can cause cellular damage and tissue necrosis due to the lack of oxygen and nutrients. Over time, the consequences of prolonged ischemia can become irreversible, leading to extensive tissue death. In extreme cases, if the affected limb is not surgically relieved of the pressure, the damage may progress to the point where the tissue can no longer be salvaged, necessitating amputation to prevent systemic complications and to preserve the health of the rest of the body.

The other outcomes listed do not align with the severe consequences of untreated compartment syndrome. For example, spontaneous healing is not possible due to the ongoing damage caused by pressure; gaining strength is counterintuitive since the tissues are dying; and there will inevitably be an impact over time as the condition worsens without intervention.