Now here is an interesting recurring question that can often be tricky to answer on the spot.
"Why is it always my left shoulder?"
"Why does my lower back always go on the right?"
"Why is all my pain on one side?"
Many people assume there must be something structurally wrong. Perhaps one leg is shorter than the other. Maybe their pelvis is twisted. Or perhaps they're convinced one side of their body is somehow "out of alignment".
Whilst these explanations are popular, they're often not the most likely reason.
In reality, pain favouring one side of the body is extremely common. More often than not, it reflects a combination of your body's natural asymmetry, previous injuries, daily habits and the way your nervous system learns from experience.
Let's look at some of the possible reasons.
Although the human body looks symmetrical from the outside, none of us are perfectly balanced.
Most people have a dominant hand, a preferred kicking foot, a favoured sleeping position, and countless daily habits that place slightly different demands on each side of the body.
Even our internal organs aren't symmetrical. Your heart sits predominantly on the left, your liver on the right, and the two sides of your brain perform slightly different functions.
A degree of asymmetry is completely normal.
The idea that the body should be perfectly balanced is appealing, but it isn't realistic. In fact, many healthy, active people have noticeable differences between their left and right sides without experiencing any problems at all.
Have you ever sprained an ankle, injured a shoulder, or suffered a bout of back pain?
Even after tissues have healed, the body often retains some memory of the event.
When we're injured, we naturally change the way we move to protect the affected area. This is a sensible and helpful response in the short term. However, some of these protective movement habits can persist long after recovery.
You may unconsciously favour one side when walking, lifting, standing, or exercising without even realising it.
Over time, these subtle changes can influence how forces are distributed through the body and may help explain why symptoms repeatedly appear on the same side.
Many of us repeatedly load one side of the body more than the other.
Perhaps you always carry a child on the same hip, sling a bag over the same shoulder, sit with one leg crossed over the other, or habitually lean to one side when standing.
Individually, these habits are unlikely to cause major problems. The body is remarkably adaptable and resilient.
However, when the same patterns are repeated day after day, year after year, they can contribute to one side of the body becoming more sensitive or more prone to discomfort than the other.
This doesn't mean you need to obsess over every movement or strive for perfect posture. It simply highlights that our daily habits can shape how our bodies respond to physical demands.
This is perhaps the most interesting explanation.
Modern pain science tells us that pain is not simply a measure of tissue damage. Instead, pain is an output of the nervous system designed to protect us.
If an area of the body has been painful in the past, the nervous system may become more alert and protective of that region in the future.
Think of it as your body's alarm system becoming slightly more sensitive in a location where it has detected danger before.
This doesn't mean the pain is "all in your head" or that the area is damaged. Rather, the nervous system has learned from previous experiences and may respond more readily when similar stresses occur again.
As a result, the same shoulder, hip, neck, or side of the lower back may become painful repeatedly, even when there is no serious injury present.
You may come across claims online suggesting that left-sided pain, in particular, is linked to emotional trauma or unresolved psychological issues.
While researchers have explored possible connections between emotional factors and patterns of pain, the evidence is far from clear-cut. Human beings are complex, and stress can certainly influence pain, but there is currently no reliable evidence that left-sided pain automatically points to a specific emotional cause.
For most people, explanations such as normal asymmetry, previous injuries, movement habits, and nervous system sensitisation are far more likely.
If your pain always seems to occur on the same side, it doesn't automatically mean that side is damaged, weak, out of alignment or wearing out.
The human body is naturally asymmetrical. It adapts to previous injuries, develops habits over time and learns from past experiences.
Pain is often less about finding a single faulty structure and more about understanding the story that your body has accumulated over the years.
So if your neck always hurts on the left, or your back always grumbles on the right, try not to assume that one side of your body is broken.
The explanation is usually far less alarming, and far more interesting, than that.
