Doing harm and reciprocating harm is not allowed.

Harm should be warded and avoided as much as possible.

All that is harmful is prohibited in Sha’riah. That will involve medicines made from porcine material, alcohol, carrion (dead animals) or seeking remedy by amulets, sorcery, and divination. Any mode of treatment that causes harm without any good is not allowed. Similarly if the harm is more than the benefit, or even if the expected harm is equal to the expected good, it is not allowed. However, if the expected benefit is greater than the harm, then it is allowed. If a patient is having a gangrenous foot or limb, and the gangrene might increase and even kill the patient, then it is allowed to amputate the limb. Similarly if a woman is pregnant and continuation of pregnancy is threatening her life, then she is allowed to abort. If the continuation of pregnancy is going to endanger her health, but not her life, or the fetus is grossly malformed, then abortion is allowed prior to ensoulment, i.e., in the first 120 days computed from time of fertilization of the ovum (i.e., conception) which is equivalent to 134 days from last menstrual period (LMP) which is used by obstetricians, and that is equivalent to 19 weeks + 1 day [3]. But it is not allowed to have abortion after that date. Yet it is possible to have preterm delivery, e.g., 36 weeks or even less if deemed necessary.

If there is certain harm, then it should be removed.

Harm should not be removed by another harm, which is equivalent to the previous harm; or worse if it is removed and replaced by a worse harm. However, if the harm cannot be removed except by accepting a lesser harm, then the lesser harm is accepted. This follows the next axiom.

The greater harm could be replaced by a lesser harm. Examples of this in medicine is amputation of a limb, if gangrene is spreading; or accepting to use narcotics to relieve pain, even if morphine and its derivative have a double effect, i.e., the debilitated patient suffering from pain due to metastasis and chronic pulmonary disease where morphine and its derivatives is going to depress the respiratory center in the medulla in the brain stem, and therefore may end in respiratory failure. The serious side effect in such a patient would be accepted if the pain was not relieved except by the narcotic. The dose should be the minimum required to alleviate pain. Muslim jurists in the past brought the case of a man who adopted Islam. He was required to circumcise his prepuce, but if that was going to harm him (there was no proper anesthetic), then he was allowed to pray and do all the required worship of Islam without circumcision.

The balancing of harms is important in Islamic jurisprudence, and if it is impossible to thwart harm, without causing another harm, then the lesser harm should be accepted.

The prohibited things would be allowed if there is necessity. If a person is lost in the desert and he is thirsty and he finds only alcoholic beverages, e.g., wine, then he is allowed to drink it to quench his thirst. Similarly, if he has no food, and only finds pork or carrion (dead meat), or blood, then he is allowed to eat it to save his life. But he is not allowed to kill another human being (a child or diseased weak person) in order to save his life. He can kill any animal that he finds or even eat the corpse of an animal or, worse, the corpse a human if there is no alternative.

In medicine the same rules may apply. Taking medicine made of porcine material or alcohol or poisonous snakes is allowed if there is no alternative medicament.

Similarly, autopsy and dissection of human bodies would be allowed in

As long as harm continues, it cannot be ignored. So long as the harmful effect is there, then it should be removed. Whatever system is there that involves harmful effects, then that harm should be removed out of the system. Otherwise the whole system should be changed. If in a certain community all foreigners officially residing in a country are not covered by health insurance or health services, that system should be changed.

The harm befalling a whole community is worse than the harm falling an individual. The general harm should be warded off first. If the general harm cannot be prevented unless it affects few, then the general harm should be prevented, even if it involves one or few individuals.

If there are two harms, then the lesser harm could be done if it is impossible to ward off both harms.

If there are two benefits, then the higher benefit should be obtained, even if it involves losing the lesser one.

If both harm and benefit are involved, then try to get the benefit and refuse the harm. If that is not possible and the benefit is much greater than the harm, then accept the lesser harm. However, if the harm is equal or even more than the benefit, then refuse the harm even if it means loss of the benefit.

“Legal permission negates tortious liability,” except in cases of flagrant negligence. These rules have great bearing in medical practice from both the ethical and legal points of view. The law differentiates between crime and tort.