It is narrated from Sayyiduna Rabi' al-Ansari (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) visited the nephew of Jabr al-Ansari (may Allah be pleased with him) in his illness. His family began weeping over him, and Jabr said to them: Do not trouble the Messenger of Allah (peace and blessings be upon him). The Messenger of Allah (peace and blessings be upon him) said: "Leave them; let them weep as long as he is alive, and when death occurs, let them be silent." Then one of them said: We did not think that your death would be on your bed; rather we hoped that you would be killed in the path of Allah with the Messenger of Allah (peace and blessings be upon him). The Messenger of Allah (peace and blessings be upon him) said: "Is martyrdom only in being killed in the path of Allah? If that were so, the martyrs of my Ummah would be very few. Indeed, dying from a spear wound and dying from the plague is martyrdom, dying from a disease of the stomach is martyrdom, the woman who dies in childbirth is a martyr, dying by burning is martyrdom, dying by drowning is martyrdom, dying by being crushed under a collapsed building is martyrdom, and dying from pleurisy is also martyrdom."
Hadith Referenceالمعجم الكبير للطبراني / باب الراء / 4592