What is Pain?
The answer to this question seems obvious - pain is pain, right?
Pain is pain, but it's not all the same. The International Association for the Study of Pain (IASP) defines pain as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage.” However, pain is a symptom that cannot be objectively assessed. I can’t look at a patient and know precisely what hurts, how badly, and what the pain feels like. Pain, therefore, is whatever the person experiencing it says it is.
Types of Pain
Pain can be divided into two categories: acute pain and chronic pain.
Acute Pain
Also known as “warning pain”, this type of pain comes on suddenly and signals that something is wrong inside the body. A classic example of this type of pain is an injury that results in a broken bone. The pain is sudden and warns the person that something has gone wrong. Infections, tumors, and internal bleeding are other examples. Acute pain can sometimes be eliminated by treating the underlying cause. A person may respond to chronic pain with fear, anxiety, and restlessness. If the underlying cause in untreatable, the pain may develop into chronic pain.
Chronic Pain
Chronic pain results when the underlying cause of pain cannot be treated. It is persistent and sometimes debilitating. This type of pain is often associated with a long-term or life-threatening illness. A person experiencing chronic pain may be depressed, withdrawn, and exhausted.
Physiological Types of Pain
It is easier to understand pain, locate its cause, and treat it by using physiological explanations of it. Pain can be divided into two types of physiological explanations: Nociceptive and Neuropathic.
Nociceptive Pain
This type of pain can either be somatic or visceral.
Somatic pain results from injury to parts of the body such as bones, joints, and soft tissues. It is usually well localized, and is often described as sharp, dull, aching, throbbing, or gnawing. Examples would include bone fractures, metastastatic cancer to the bone, tumors, and arthritis.
Visceral pain results from inflammation, distension, or stretching of the internal organs. It is not well localized and is often described as aching, cramping, deep pain, or pressure. Examples would include pain in the abdomen from a bowel obstruction and left arm/jaw pain from an acute myocardial infarction (heart attack).
Neuropathic Pain
Neuropathic pain results from injury to nerves in either the central nervous system or the peripheral body. It can be described as burning, tingling, shooting, stabbing, or shocking. Injury to the brain, brain tumors, diabetic neuropathy, and herpes zoster are all examples of things that may cause this type of pain. Neuropathic pain can be more difficult to treat than nociceptive.
Pain and Palliative Care
A person on palliative care or hospice may experience different types of pain. Pain may be related to the underlying disease or the hospice diagnosis. This type of pain is usually defined as chronic pain and can either be nociceptive or neuropathic. A person on palliative care or hospice may also experience acute pain. Some examples include pain from pressure ulcers (bed sores), injury from falls, or side effects from the underlying illness like internal bleeding secondary to liver disease.
Regardless of the type of pain, the severity of it, or the cause, palliative care and hospice are well equipped to treat it. Pain management is a primary goal of comfort care.
Sources:
The International Association for the Study of Pain (IASP) definition of pain. http://www.iasp-pain.org
Kinzbrunner, Policzer, and Weinreb: 20 Common Problems: End of Life Care
