Pain. It is both debilitating and scary.
What is causing it? How long will it last? Will it ever go away? How serious is it?
It could be something that starts off as a simple sharp stitch on the left side of your back but then slowly grows worse with each day that passes.
When it comes to pain the four most common types of chronic pain that people experience are back pain, headaches, joint pain and nerve pain.
Doctors advise us to avoid Googling our symptoms, but when you are experiencing acute pain that isn’t going away, it can be almost too hard to resist.
How do you know if it is just back pain, or if it is something more serious?

How Serious Is It?
Back pain is a common occurrence in the US with more than 80% of the population experiencing it at some point in their lives. Back pain can radiate from bones, muscles, ligaments, joints, or many other parts of the body. Everything from posture and activity levels to diet and obesity can contribute to low back pain.
But when the pain is located specifically on one side, you might wonder if it is just low back pain, or something more serious?
The good news is that one-sided back pain is actually a fairly common issue, but it can have some very different causes. Some causes are more serious than others and should definitely be checked out by your healthcare provider.

Causes
When it comes to lower left back pain the most common causes are:
Soft tissue damage of muscles or ligaments that support the spine
Injury to the spinal column, like the discs or facet joints
Internal organ issues such as the kidneys, reproductive organs, or the intestines.

Soft Tissue Damage
Most episodes of acute lower back pain are caused by damage to your soft tissues, such as the muscles and/or ligaments that support your lumbar spine. These episodes can occur after injuries such as falls from a ladder, a car accident, or a sports injury. They can also be caused by poor posture, especially if you spend a big part of your day sitting in the wrong position.
Typically soft tissue injuries, or sprains, cause pain in the middle of the spine, but they can lead to pain that is specific to either the left hand side of the back, or the right hand side.
Muscle strain occurs when the muscle fibers overstretch, leading to inflammation, and it is the leading cause of low back pain on the left side.

Symptoms of soft tissue damage include:
Limited range of motion
Stiffness
Muscle spasms
Tenderness or swelling of the affected area
Pain that gets worse after sitting or getting out of bed
Pain that improves with rest, ice or NSAIDs
Treatments:
Mechanical stimulation/ massage
Ice therapy
Topical pain reliever

Slipped Discs
A slipped disc (also known as a herniated disc) can cause pain that radiates from the central spine to one side of the back or the other. The bones in the spine are cushioned by small discs that have a firm outside and a liquid inside which acts as a barrier between each bone.
A slipped disc occurs when fragments of the inside push through tiny tears in the outside of the disc. This material then presses on the nerves, causing the pain. Slipped discs can develop over time due to general wear and tear, or they can be caused by an injury.
Symptoms:
Tingling down one leg
Pain that gets worse when you walk
Pain on one specific side of the body.

Treatments:
1–2 days of bed rest
NSAIDs

Internal Organ Issues
When it comes to low back pain, specifically on one side of your body, internal organs might not be the first thing that comes to mind. Organs such as your kidneys, pancreas, colon and uterus can become infected, irritated or inflamed, causing sensations of pain in your back.
Kidney infections, kidney stones, pancreatitis, ulcerative colitis or fibroids, can all cause pain that radiates down your back. Typically these conditions are easier to distinguish from general low back pain as they are often accompanied by other symptoms.
These symptoms can include:
Fever
Nausea
Abdominal pain
Fatigue

Treatments:
A proper diagnosis is required for internal organ issues. Treatments can range from antibiotics to surgery, so, if you suspect that your low back pain could be due to one of these conditions, consulting with your healthcare provider is a must. They will be able to refer you for further testing, if required, or to see a specialist for your condition.

Emergency Symptoms
Although it is quite rare, sometimes low back pain can be accompanied by other symptoms which can indicate something much more serious. Emergency symptoms that cause back pain aren’t always associated with your back.
They could be signs of something else that is not related. If you suspect that something else is going on, rather than just regular low back pain, do not hesitate in getting to the emergency room. You should also head straight to the emergency room if you experience any of the following symptoms/ red flags:
Nausea
Vomiting
Shortness of breath
Dizziness
Confusion
Tingling in your lower body
Unusual weakness in your lower body
Fever
Chills
Incontinence
Blood in your urine
Painful urination

Conclusions
As you can see, pain in your lower left back can have quite a few different causes, and the treatments can vary widely. This makes getting an accurate diagnosis even more important.
Your local emergency room or healthcare provider can perform a physical exam, take a full medical history and do a thorough review of symptoms before making an official diagnosis. They can also refer you for further diagnostic tests if they think those will be helpful.
The good news is that most cases of low left back pain are due to strains and sprains that can heal themselves fairly quickly with some minimal interventions. Always trust your instincts, though, and if you suspect that you have any other concerning symptoms that are accompanying your back pain, then definitely seek medical attention.