Sign In

Why we still don’t understand chronic pain

Chron­ic pain is the 21st-cen­tu­ry curse. It blights the lives of mil­lions and impos­es a huge bur­den on health and care sys­tems.

It blights the lives of mil­lions and impos­es a huge bur­den on health and care sys­tems

Despite advances in med­ical sci­ence, we are often at a loss to under­stand what caus­es chron­ic pain or how it should be treat­ed. What’s more, the opi­oid drugs which had become the default option to help peo­ple man­age it are under intense scruti­ny because of their high risk of depen­den­cy and harm­ful side effects.

Number of people with chronic pain is rising

Inci­dence of chron­ic pain is increas­ing. This is part­ly down to an age­ing pop­u­la­tion, with old­er peo­ple more like­ly to suf­fer with back or nerve pain and long-term con­di­tions such as arthri­tis and rheuma­tism. Our seden­tary lifestyles and an increase in obe­si­ty are also to blame.

Eco­nom­ic cost is dif­fi­cult to quan­ti­fy, but back pain alone accounts for around £10 bil­lion a year in sick­ness absence.

The def­i­n­i­tion of chron­ic pain is itself fair­ly arbi­trary, usu­al­ly tak­en to mean pain that lasts for more than 12 weeks. Accord­ing to the British Pain Soci­ety, more than two fifths of the UK pop­u­la­tion live with chron­ic pain. That’s around 28 mil­lion peo­ple who face a dai­ly strug­gle to live their lives as they would wish.

At a fun­da­men­tal lev­el, chron­ic pain is a mat­ter of biol­o­gy. Nerve impuls­es alert the brain about tis­sue dam­age that no longer exists, if it ever did. But com­plex social and psy­cho­log­i­cal fac­tors are also at play, and they seem to help deter­mine why some peo­ple cope bet­ter than oth­ers with chron­ic pain.

Pain is difficult to measure and to treat

Some­times the caus­es of chron­ic pain are obvi­ous, such as a phys­i­cal injury or an ill­ness. But there may also be no clear cause. Pain is a very per­son­al and sub­jec­tive expe­ri­ence.

There is no test that can mea­sure and locate pain with pre­ci­sion. Chron­ic pain may occur in a vari­ety of loca­tions in the body and for many dif­fer­ent rea­sons. So health pro­fes­sion­als rely on the patient’s own descrip­tion of the type, tim­ing and loca­tion of pain. This makes diag­no­sis dif­fi­cult and com­pli­cates the process of iden­ti­fy­ing effec­tive treat­ment.

Despite decades of research, chron­ic pain remains noto­ri­ous­ly hard to con­trol and there is an over-reliance on opi­oid painkillers. A sur­vey by the Amer­i­can Acad­e­my of Pain Med­i­cine found that even com­pre­hen­sive treat­ment with painkilling pre­scrip­tion drugs helps, on aver­age, only about 58 per cent of peo­ple with chron­ic pain.

Even though doubts exist about their effec­tive­ness in help­ing to man­age chron­ic pain over long peri­ods, there has been a steep increase in pre­scrip­tions of opi­oid drugs in Eng­land and Wales. The num­ber of pre­scrip­tions for opi­oids, such as mor­phine and fen­tanyl, has risen from 14 mil­lion in 2008 to 23 mil­lion last year.

The Depart­ment of Health and Social Care has ordered man­u­fac­tur­ers to pro­vide warn­ings on their labels, say­ing the drugs can cause addic­tion. This also includes over-the-counter codeine-based painkillers which, although weak­er in strength, can also cause depen­den­cy.

Pain and mental ill health are often intertwined

It is worth bear­ing in mind that until the late-1990s, opi­oids were usu­al­ly restrict­ed in the UK to can­cer patients and for those in acute pain fol­low­ing surgery, but sub­se­quent­ly they were increas­ing­ly pre­scribed for chron­ic pain.

But if access to opi­oids is to be restrict­ed, what are the alter­na­tives? More and more, health pro­fes­sion­als are being trained to take a holis­tic approach, address­ing a patient’s men­tal health and emo­tion­al well­be­ing as well as their phys­i­cal health.

Neg­a­tive emo­tions, includ­ing sad­ness and anx­i­ety, seem to aggra­vate chron­ic pain. For exam­ple, peo­ple who dwell on their dis­com­fort tend to be more dis­abled by chron­ic pain than those who try to take pain in their stride. And among peo­ple with chron­ic pain stem­ming from a work-relat­ed injury, those who report poor job sat­is­fac­tion fare worse than those who say they like their jobs. How­ev­er, neg­a­tive emo­tions can be a result of chron­ic pain as well as a cause.

There are phar­ma­co­log­i­cal alter­na­tives to opi­oids. These include non-steroidal anti-inflam­ma­to­ries which help to reduce swelling that is the cause of much chron­ic pain. Tri­cyclic anti­de­pres­sants can be effec­tive in treat­ing nerve pain. A class of med­ica­tion called gabapenti­noids, orig­i­nal­ly used as anti-seizure drugs, is use­ful in calm­ing over-fir­ing nerves.

Are there any cures for chronic pain? 

Localised numb­ing of prob­lem areas can also help. For exam­ple, patients under­go­ing shoul­der surgery receive an injec­tion of anaes­thet­ic in the low­er neck that numbs the area for 18 hours. Mean­while, non-drug treat­ments, such as ice, mas­sages, acupunc­ture and relax­ation train­ing, can be espe­cial­ly use­ful in treat­ing chron­ic pain.

A short course of phys­i­cal ther­a­py by a physio or occu­pa­tion­al ther­a­pist can help patients to move bet­ter, relieve pain and make dai­ly tasks, such as walk­ing, climb­ing stairs and get­ting out of bed, eas­i­er. Treat­ment involves stretch­ing exer­cis­es and manip­u­la­tion to improve move­ment.

Although sig­nif­i­cant gaps remain in our under­stand­ing of chron­ic pain, we have come a long way since the days when doc­tors rec­om­mend­ed bed rest for weeks or months on end. We now know that this is the worst pos­si­ble approach. Exer­cise and work are key to recov­ery. The goal of mod­ern treat­ment is to reduce pain and improve func­tion, so patients can resume day-to-day activ­i­ties.

Patients and their health­care providers have a num­ber of options for the treat­ment of pain. Some are more effec­tive than oth­ers. What­ev­er the treat­ment plan, it is impor­tant to remem­ber that chron­ic pain usu­al­ly can­not be cured, but it can be man­aged.