The Hulk possesses the capacity for superhuman strength ranging beyond the limits of virtually any other known humanoid being. The gamma radiation that mutated his body fortified his cellular structure and added, from some as yet unknown (presumably extradimensional) source, several hundred pounds of bone, muscle and other tissue. In times of stress the Hulk's adrenalin level escalates, causing a corresponding escalation of strength. Thus, the madder the Hulk gets, the stronger the Hulk gets. This is usually not accompanied by an additional gain of mass, but does appear to promote increased levels of energy efficiency.

The Hulk has not yet found an endpoint to his maximum strength, so its upper limit remains a mystery. While described as Class 100 strength, the Hulk has at times proven capable of exceeding this parameter several times over; following exposure to the warp core breach on planet Sakaar, his baseline strength is even higher.

The Hulk periodically reverts to the human form of Bruce Banner, losing his extra mass and energy to the same source from which he derived it. The Hulk differs from many other gamma-irradiated human beings in that Banner was outside, exposed to sunlight, during his first heavy exposure to gamma radiation. This at least partially explains why the Hulk's color was initially gray, not green like most other gamma mutations. Moroever, this is also part of why Banner transformed into the gray Hulk at nightfall and reverted to human form at the coming of dawn; however, it was later revealed that this was also partially due to Banner's shame over being the Hulk, and that he subconsciously forced himself to revert to human form in daylight to avoid being seen in his monstrous Hulk form. Though he has since managed to become the gray Hulk in daylight, he sometimes feels a burning sensation from sunlight contacting his skin.

The process by which Banner usually transforms into the Hulk has a chemical catalyst, adrenalin (aka epinephrine). As in normal human beings, Banner's adrenal medulla secretes huge amounts of adrenalin in times of fear, rage or stress, which hormonally stimulates his heart rate, raises blood-sugar levels and inhibits sensations of fatigue. Whereas the secretion heightens natural physical abilities in normal human beings, in Banner's case it triggers the complex chemical extra-physical process that transforms him into the Hulk.

The total transformation takes anywhere from seconds to as long as 5 minutes, depending on the initial adrenaline surge, which is determined by the original external stimulus. Soon after the transformation, Hulk's adrenalin levels will return to more normal, reduced levels. At various times in his life, Banner has been able to mentally control the change, producing or inhibiting it in either direction. At many times in the past, Banner would revert to the Hulk, regardless of the time of day or night, whenever he underwent enough excitation to induce a sufficient surge of adrenalin to trigger the transformation. Similarly, often if the Hulk relaxed to a great enough degree, his adrenalin levels would decline and he would revert to human form; however, there are many known instances in which the Hulk was very relaxed or even slept without reverting to human form.

The Hulk is superhumanly durable and resistant to pain and disease. His skin can resist great heat without blistering (even tolerating the Human Torch's nova flame), great cold without freezing (down to absolute zero, -460 degrees Fahrenheit), and great impacts (he can survive direct hits by field artillery cannon shells or falls from the edge of the atmosphere).

While it is possible to injure him, the Hulk also has vastly superhuman healing, enabling him to regenerate body tissue (including internal organs) within seconds to minutes; it once took him weeks to recover from a broken neck. It is not known what type of injury could kill the Hulk, but one of his alternate future counterparts was disintegrated by a nuclear level explosion, though he eventually reintegrated his form over a period of several years.

The Hulk's highly efficient physiology renders him immune to all terrestrial deseases, and possibly to aging; yet the Maestro is an aged Hulk version from a potential future. Though Banner's form does not appear to share these immunities, some injuries will heal via transformation into the Hulk and vice versa.

The Hulk can hold his breath for about an hour; his superhuman durability allows him to survive in the vacuum of space or at the ocean floor, though he would suffocate if too much time passed or if he were forced to expel his retained air.

In particular, the Hulk is resistant to radiation, though in some circumstances, gamma radiation exposure has caused him to revert back into Banner. Similar effects have been achieved by draining the gamma radiation from the Hulk, or by exposing him to an uncertain type of radiation referred to as "gamma-negative rays".

Visit the Different Incarnations/Personalities page.