Pain, it has been said, is one of nature’s first signs of illness. Most will agree that pain stands preeminent among all unpleasant sensory experiences by which people perceive disease within themselves. There are very few illnesses which do not have painful phases.

In many conditions, pain is characteristic of the illness, without which the diagnosis must remain in doubt. In order to understand the subject of pain, every individual should understand normal anatomy. Pain is perceived as an unpleasant sensation, because of the stimulation of certain nerves in the skin or internal organs.

These electrical messages are carried through our nerves to the spinal cord, then up specific pathways to the brain. An unpleasant sensation is first perceived in a portion of the brain called the thalamus. A rendezvous with nerve connections to the highest nerve centers, finally sends a message on to the cortex, our outer covering of the brain.

There it is interpreted as to location, type, intensity, and integrated with past experiences and avoidance mechanisms that will protect your body from damage. Pain may be perceived from any of your nerves. Cold, heat, pin prick, pressure, muscle spasm, distention of hollow organs, lack of oxygen to certain areas, and other stimuli may be perceived as pain.

Some types of pain, such as phantom pain, occur after an amputation, following less known pathways, but presumably they result from irritation of nerve endings. Direct pressure on a nerve, as in degenerative disc disease of the spinal column or other conditions where peripheral nerves are compressed can also be painful.

Infections of the nerves, such as that produced by the shingles virus may produce severe unrelenting pain. So, there are many mechanisms, many syndromes, and a most careful study is necessary to understand the causes of the pain response. Several types of pain can be confused. The stimuli that arouses pain varies from organ to tissue.

For example, the intestinal tract is not responsive at all to pin prick, burning, cutting or pressure. But it responds with exquisite pain to the distention produced by stretching, as in an obstruction or the mere presence of excessive gas. In contrast, the skin is exquisitely sensitive to pin prick, burning, freezing, and cutting.

Each of these sensations is carried through separate nerve receptors. The nerve impulse is mediated by specific chemical agents. Such substances as acetylcholine, serotonin, histamine, and bradykinin are released by tissue injury, and have been found to elicit pain when applied to the base of a blister. It is felt that the threshold for perception of pain is approximately the same in all persons.

This threshold is lowered by inflammation, in alcoholics, and is influenced by certain other analgesic drugs as well as strong emotions, such as fear or rage. Greatly varying, however, is the degree of emotional reaction, and the verbalization (or complaint) in response to pain. The personality and character of the individual influences this reaction greatly.

Superficial Pain

The largest pain fibers are used in transmitting a pricking type of pain. Sharp sensations are conducted much more rapidly than a sense of burning. Most normal individuals can localize instantly such pains with precision. This surface sensitivity to the place where a stimulus is applied helps us distinguish superficial pain from deeper types.

Visceral Pain

Deep pain, including that of the internal organs and skeletal structures, has basically the quality of severe aching. However, intense, visceral pain may also be sharp or knife-like. Occasionally there is a burning type of deep pain, as in the case of heartburn from esophageal irritation, and rarely, in the angina pectoris of heart disease.

These pains are felt beneath the body surface. Localization is poor and the margins of pain are not well outlined, presumably because of the scarcity of nerve endings in these organs.

Deep Musculoskeletal Pain

The same common nerve system transmits the impulse of both deep skeletal pain and visceral pain. Hence, their characteristics as to type, localization, and referral are similar. These pains are usually corresponding to the nerve roots coming from the spinal cord. A knowledge of nerve anatomy helps to localize these pains as to origin, although the exact origin is often obscure.

Referred Pain

Deep pains within the body organs tend always to be referred to the surface structures within the similar and corresponding spinal segment. In the case of pain from the heart muscle, these nerve impulses refer such pain primarily to the chest wall overlying the heart.

Sometimes this extends up to the shoulder and the neck, most commonly on the left side. Pain from the rectum, prostate or female organs is usually referred into the low back. Sometime the back of the neck is involved in the referral from pain in the sinus region.

Since a similar nerve innervates the shoulder and the diaphragm, irritation under the diaphragm as in a liver or gallbladder condition, or upper abdominal abscesses can be felt near the shoulder blade.

Radicular Pain

This type of pain usually refers to the shooting extension of pain from the neck or low back. A disc that is pinching part of a root of the sciatic nerve usually sends a shock-like sensation down the nerve along the side or the back of the leg.

This may coexist with numbness in the involved extremity, and, at times, weakness or lack of reflexes can also be seen. Similar types of radicular pain are present in the upper extremities from disease in the spine at the neck.

Psychological Aspects of Pain

The emotional state can influence greatly the perception of pain and its effect upon the body in general. Ambrose Pare, a French Huguenot barber and surgeon, remarked, “There is nothing that abateth so much the strength, as pain.” Continuous pain can be observed to have an adverse effect on the entire nervous system.

There is increased irritability, fatigue, troubled sleep, poor appetite, and loss of emotional stability. Courageous men are sometimes reduced to a whimpering, pitiable state in their reaction to severe pain. They become irrational about illness and may make unreasonable demands on their family.

This condition is sometimes called “pain shock,” and, when established, requires delicate, but firm management. Depression is common, especially in chronic pain syndromes. At times unfortunately, the demands for and dependency on narcotic drugs often complicate the picture.

Special Types of Pain

Headache

The term headache encompasses all aches and pains associated in the head. Along with fatigue, hunger, and thirst, headache represents man’s most frequent discomfort. It must always be kept in mind that headache is a symptom, not a disease, and its cause should always be ascertained.

Some types of headaches are quite easy to diagnose. Infection or blockage of sinuses is usually accompanied by pain over the sinus area and in the forehead. It is often associated with tenderness of the skin in the same area. Sometimes the head seems to throb. Often headaches tend to return at the same hour of the day.

Headache originating in the eye is usually located near the eye or in the forehead. It is of steady, aching type and tends to follow prolonged use of the eyes in close work. Muscle imbalance is often involved. A careful examination of the eyes by your doctor is recommended.

Headaches accompanying diseases of the ligaments, muscles, and joints in the upper spine are usually referred to the back of the head and nap of the neck. Later in life, these pains are seen frequently in arthritis and also tend to occur after whiplash injuries.

Massage very deeply in the area and you may disclose the presence of tender nodules near the insertion of the neck muscles. Moist heat, as well as skillfully performed massage is particularly helpful in relieving this type of pain. The headache of irritation in the meninges or coverings of the brain, is usually of an acute onset and becomes severe, deep seated, and constant.

Usually this occurs in conjunction with fever. Whenever the neck becomes stiff, immediate consultation with a physician is recommended. Both meningeal infections or brain hemorrhages can cause this type of pain. Lumbar puncture in about 20% of normal patients may produce a transient headache. Usually this is relieved in the lying position and subsides after a few days.

Migraine

The term migraine refers to periodic, throbbing headaches on one side of the head, which usually begins in childhood or adolescence, and occur with diminishing frequency during advancing years. Sometimes, along with the headache, nausea and vomiting may actually disable the affected individual for several hours each time the migraine occurs.

Some variations are seen. Many are forced to lie down and to shun light and noise for what they call a “sick headache.” Other milder forms do not require withdrawal from accustomed activities. Between attacks the migraine sufferer is essentially normal.

In fact, the headache seems to be brought on during the “let down” period after many days of hard work or stress. Spasm in the blood vessels has been implicated and many powerful hormones are often released that perpetuate discomfort for several hours.

Tension Headache

This type of headache usually occurs over both sides of the head and often settles at the base of the neck. A fullness, tightness, or pressure is often described. Sometimes these headaches show the peculiarity of being continuous day and night for long periods of time. Sustained muscle tension, as well as vascular changes may be involved.

Sometimes a similar headache may follow injury (auto accidents, head trauma) and gradually resolves over many months. Simple remedies may be used with success in the treatment of headache. A person should lie down in a quiet area, apply a cold compress to the head, and seek to put the mind at rest.

Often a drink of water or mild nerve-calming tea such as catnip or chamomile tea can relax the person until the headache passes. More severe types of headaches can be treated with the hot foot bath. This is described in the section on hydrotherapy.

Adding mustard to the foot bath may also bring relief through acting as a counterirritant as well as pulling blood to the lower extremities (called derivation) to relieve congestion in the head. Extra hours for sleep, daily nature walks, or a change of pace may be needed. General hygienic recommendations for a more healthful diet, systematic exercise, and improved stress control are valuable preventives.

Chest Pain

There is very little parallel between the severity of chest pain and the seriousness of its cause. A frequent problem exists in distinguishing trivial disorders from coronary artery disease or other serious health hazards. It is important to avoid the long tradition now shown to be myth, that pain beneath the left breast or radiating into the left arm is always of cardiac origin.

Such pain is often observed in patients who are tense, easily fatigued, or anxious. Oxygen deficiency of the heart muscle can produce pain. This is the syndrome medically termed angina pectoris. When the oxygen supply is deficient in relation to the need, pain will develop in the heart muscle.

This may be aggravated by exercise, or occur during a stressful situation, or after a heavy meal. Atherosclerosis (narrowing) of the coronary arteries is the most common cause. Spasms of the small cardiac vessels may also trigger this pain (angina), which usually subsides with a short rest.

Pain in the esophagus usually results from acid irritation of the lining (mucous membrane) of the esophagus. Spasm of the swallowing muscles or the presence of obstruction can also produce this deep chest pain. Accompanying symptoms of difficult swallowing, regurgitation, and weight loss direct attention to the esophagus.

Pain in the pleura or the lining of the lung is very common. It results from stretching of the inflamed membrane and occurs in viral, as well as bacterial, pneumonia. Sometimes air in the chest cavity (pneumothorax) and tumors can mimic this type of pain. Inflammation of the outer covering of the heart (pericarditis) can also produce it.

It is usually aggravated by coughing or deep breathing. Sometimes swallowing or a change in bodily position produces the same type of pain, Applications of moist heat and rest are important in the relief of these deeper pains. Tension is also a common cause of chest wall pain.

Usually the discomfort is experienced as a sense of tightness, sometimes called aching. It may occur on various occasions and in different areas of the chest, and is usually associated with fatigue or emotional strain. It is important to distinguish these and the above categories of chest pain from various abdominal problems, some of which are described below.

Abdominal Pain

The correct interpretation of acute abdominal pain is one of the most challenging demands made of any physician. Sometimes proper therapy requires urgent action. A great deal of experience and judgment is needed to elucidate the cause. A number of mechanisms can produce abdominal pain. Inflammation of the lining of the abdomen (peritoneum) can produce pain of steady, aching character.

This pain is usually located directly over the inflamed area and the area will also be quite tender. Release of a small amount of stomach acid will cause much more pain than even contaminated intestinal contents will when the appendix ruptures. Another type of pain occurs in the distention or obstruction of hollow organs.

This is usually intermittent or cramping in nature. Colic in the abdomen can be produced from obstruction of bile duct, the gallbladder, the ureters, or the intestines. Since all of these may cause vomiting, the location of the pain and other related symptoms must be considered in arriving at a rapid diagnosis.

Finally, it is important to consider the blood vessels in the abdomen as causes of potential pain. An out pouching of the aorta (aneurysm) may produce pain, developing slowly, increasing gradually, or in a sudden rupture, may become quite catastrophic.

Abdominal angina occurs when the vascular supply to the intestines becomes clogged with cholesterol deposits and this pain, similar to the angina pectoris of the heart, occurs following a heavy meal. Referred pain from the chest, the spine, or the pelvic organs, may also make diagnosis difficult. Compression or irritation of nerve roots in the spine is usually intensified by coughing, sneezing, or straining.

Pressure on the genital organs will usually be very painful and show the origin immediately of this referred pain. Respiratory origin is usually indicated by obvious interference with breathing. It is important to become acquainted with the clinical pictures of these various abdominal problems. Knowledge of anatomy of abdominal organs, as well as their function is essential in understanding abdominal pain.

Some types can be treated safely at home. In these cases, moist heat and temporary abstinence from food is often helpful. There are conditions requiring surgical intervention. Basically keeping in mind these possibilities will help an individual to seek a physician promptly at the appropriate time while avoiding unnecessary dependence on drugs or expensive diagnostic testing in the more self-limited and trivial conditions.

Back Pain

Pain in the lower back, as well as the neck is very common in America. Many related, but distinct conditions can produce discomfort here. Disease of the spine, although less common than other problems, is often related to injury.

An auto accident or sudden fall, causing acute flexion of the back, may compress and fracture one of the vertebral bodies. It may be an early sign of osteoporosis, thinning of the bones due to calcium deficiency.

X-ray is often necessary to diagnose this condition accurately. Immobilization on a straight board, with the avoidance of any flexion, standing, or walking is extremely important First Aid in dealing with these acute injuries. Braces, which keep the back in extension, are often worn for several months in the treatment of a fractured spine.

Local pain in the low back can be caused by any process, which irritates nerve endings. Straining of the muscles, protrusion of a disc, rupture of a ligament, and many less common problems can injure the tissues and aggravate this pain. Tenderness is usually found upon pressure in the region involved.

Associated muscle spasm may produce pain around the involved area. At times, the pain may be referred or projected into regions lying in the area of the associated nerve roots. For example, pain produced by diseases in the upper part of the lumbar spine is usually referred to the front of the thighs and legs.

That from the lower part of the lumbar spine, is referred to the buttocks, posterior thighs, and calves. Radicular or root pain has some similar characteristics, but usually is much more intense and is often aggravated by a cough, sneeze, or strain. Any motion, which stretches the nerve, such as straight leg raising, may have a similar effect.

Proper examination of the back is an art requiring considerable knowledge of muscle, nerve and skeletal anatomy. Often tenderness over the lumbosacral junction, the sacroiliac joint, the costovertebral angle over the kidneys, or a specific vertebra can help the examiner in accurate diagnosis.

The usual testing of the blood, urine, and x-rays of the back are often adjuncts in understanding the cause. Appropriate exercises may then be used, together with rest or the use of moist heat in bringing relief to all but the most stubborn condition. Special problems may be treated effectively in a lifestyle center.

Musculoskeletal Pain

Pain involving the ligaments and muscles is often seen in athletic injuries. When the ligament is torn, the injury is called a sprain. This often occurs in the ankle, the knee, the low back, or shoulder. Muscles that are bruised often become painful and when the injury is considerable, that is called a strain.

These small ligaments and muscle fibers may actually be torn, but heal without any residual weakness, after a short period of rest. Inflammation of the bursa (bursitis) may occur as the result of trauma, arthritis, infection or other disorders. Common locations include the shoulder, hip, knee, elbow and heel.

Severe local pain and tenderness is often present. Sometimes calcium deposits are seen on x-ray. Immediate application of cold in the form of snow or an ice bag is one of the most helpful remedies, followed by mild exercise and gentle hot and cold compresses, after the acute inflammation subsides.

The tendon sheath of the hand or wrist may become inflamed, Some of these are due to constriction of tendons or nerves, and may require surgery. In the wrist this is called carpal tunnel syndrome. Others are seen in conjunction with rheumatoid arthritis.

A number of metabolic problems can produce skeletal pain, muscle cramps, or deep visceral pain. The sudden restriction of oxygen supply, disorders of the adrenal glands, and the so-called autoimmune diseases, may produce severe weakness or muscle pain. Three forms of vascular obstruction particularly deserve mention.

Arteriosclerosis of the large and medium sized arteries is the most common vascular disease of man. This often leads to pain in the muscles, particularly in the legs induced by exercise (intermittent claudication). Diabetic patients are particularly susceptible. Often the pulses in the lower extremities are reduced.

Changes occur in the skin with hair loss, deterioration of the nails, and even gangrene. Buerger’s disease (thromboangiitis obliterans) is a disease of young and middle-aged male cigarette smokers. This hypersensitivity to tobacco produces spasm in the small vessels of the hands and feet.

Sometimes a smoker is so addicted to nicotine, that he continues to pursue the habit, in spite of progressive gangrene and amputation of fingers, feet, legs, and even hands. I have often seen these unnecessarily handicapped patients suffering the terrible sequels of nicotine addiction.

Raynaud’s disease is often caused by cold. Women are most commonly afflicted. With exposure to cold, their fingers become white, then blue, and finally red. Pain and tingling are common during this crisis, due to the lack of blood supply. Exercising by whirling the arm in a windmill motion can help to bring blood to the involved areas.

Another occupational complication of a similar nature may produce ulceration in fingertips or toes. These are more commonly seen in smokers and those with auto-immune disorders. Obstruction of the lymphatic return may produce a type of edema, associated with pain.

Also, thrombosis of the veins is usually painful, involving the overlying skin with redness and swelling. When larger veins are involved, the muscle and entire extremity is very painful. Most of these pain syndromes can be approached effectively by the intelligent home health observer.

With a knowledge of anatomy and physiology, and a few simple remedies, they can bring relief to many cases. It is important first to ascertain the cause of these pain responses. Wrong habits may need to be corrected.

Then nature is assisted in her efforts to restore right conditions within the nerves, muscles, and other involved organs. The relief of pain will always evoke profound gratitude from chronic sufferers. Its study can challenge the layman or specialist for at least a lifetime.