Pain is a sensory and emotional experience that causes discomfort, and it’s our body’s way of telling us something is wrong – most often, some form of tissue damage. One of the most disabling problems in the United States, pain has historically been understood as an important symptom of other medical conditions. 

“In fact, many would argue and data suggest that it’s the most common symptom that leads people to seek health care,” says Robert D. Kerns, PhD, professor of psychiatry, neurology and psychology at Yale School of Medicine. “The most common presenting complaint, maybe with the exception of symptoms of the common cold, is pain.” 

Today, researchers have a better understanding of pain as a disease. Using new methodologies to study the brain and the central nervous system, researchers are now focusing on chronic pain that persists despite the resolution of an underlying injury or structural pathology that may have been the pain's initial source. 

“Pain is a problem that doesn’t fit the mold,” says Kerns. “It’s such a widespread problem, owned by everybody, and hence nobody. If you think about it, it’s quite profound. There is perhaps no bigger public health problem.”

The feelings you may experience can be different from person to person, from joint pain to muscle cramps. The most common types of pain are:

• Acute Pain. This type of pain is categorized by a sharp and temporary pain. The source of acute pain is often damage to bones, joints, muscles, or organs.
• Chronic Pain. Persistent pain that’s resistant to treatment is known as chronic pain. Causes of chronic pain can, like acute pain, include tissue damage but may also include nerve damage, which is often the most difficult form of chronic pain to treat. Diseases such as osteoarthritis can also cause chronic pain.

Pain can be associated with other medical conditions like musculoskeletal conditions, such as low back pain. Or the discomfort can also be secondary to a much range of medical conditions, from fractured bones to cancer.

"All the things that we understand have negative effects on a broad array of health conditions and are contributors to other medical problems – those are similarly predictors of pain, and chronic pain in particular,” Dr. Kerns says.

An inactive, sedentary lifestyle may contribute to common complaints such as back and joint pain. Activity and movement can help reduce pain. For some chronic pain conditions, genetics may be involved. Conditions such as osteoarthritis and lupus appear to be hereditary. Age can also play a role in pain. As people age, they become more prone to conditions such as arthritis that causes chronic pain.

Whether pain is acute or chronic, a doctor will conduct a comprehensive assessment that can lead to the diagnosis of an underlying condition that needs to be treated. Depending on the source of the pain, your may work with a primary care physician, physical therapist, neurologist, mental health professional, orthopedic surgeon, or rheumatologist for treatment.

Treatment of an underlying cause can take many forms and should be done as early as possible to avoid further complications. Concurrent with that treatment, a person may choose additional options to directly address the pain.

• Medication. Over-the-counter pain medications such as acetaminophen and non-steroidal anti-inflammatories such as aspirin and ibuprofen are often the starting point for addressing pain, as there are few side effects. Prescription pain medications, such as the class of opioids that includes drugs such as Vicodin, may be administered judiciously. But because of the addictive potential of those prescription drugs, many doctors will aim for a different method of treatment if possible.
• Physical Therapy. A physical therapist can help manage pain with specifically focused body movements, such as stretching and other motion exercises that also can improve strength and flexibility.
• Surgery. If all other modes of treatment have been unsuccessful, a doctor may recommend surgery, which can include spinal fusion or disk replacement. Surgery may ease the initial source of pain, but comes with additional risks. 
• Mental Health Counseling. Chronic pain can cause not just physical symptoms, but also emotional ones such as depression or anxiety. A mental health professional can help a person deal with those symptoms by focusing on detrimental thoughts and behaviors and developing strategies to replace those with more positive and productive habits.

A collaboration between the Department of Veterans Affairs and Yale Medicine has led to the establishment of the Pain Research, Informatics, Multi-morbidities, and Education (PRIME) Center at the VA Connecticut Healthcare System. This is the only federally financed research center that has a specific and unique focus on pain and pain management. Much of the pain research underway at Yale Medicine involves investigating how to prevent acute pain from becoming chronic. 

“Looking at large population-level databases, and drawing what we can from existing data, we’re identifying factors and variables that seem to be early predictors of these points of transition,” Kerns says. “We’re designing interventions to target people with pain who are also tobacco users to see if an integrated approach may not only help people quit their use of tobacco, but also experience reductions in pain,” Kerns says. 

The question, he says, is: “Can it be an effective pain treatment to help people quit smoking?”