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What Is the Loin? Unveiling the Anatomy, Cuts, and Culinary Uses

Editorial Team
Editorial Team
Editorial Team
Editorial Team
What Is the Loin?

Discover the intricacies of human anatomy as we explore what the loin is—a region that plays a pivotal role in our body's structure and function. According to the American Council on Exercise, the muscles in the loin area, particularly the lower back muscles, are crucial for maintaining proper posture and stability, with 80% of adults experiencing lower back pain at some point in their lives due to weak or injured muscles in this region. The loin extends vertically from just beneath the ribcage to below the pelvis, encompassing the flanks and lower back adjacent to the spine. This term, rooted in the Latin word 'lumbus,' may also encompass the reproductive organs, groin, hips, and lower abdomen. Understanding the loin's anatomy is essential for both medical professionals and individuals aiming to optimize their physical health.

 

Doing a lunge can help stretch the psoas muscle, which is related to the loin.
Doing a lunge can help stretch the psoas muscle, which is related to the loin.

Loin is not a term commonly used by doctors or in medical science. In the field of medicine, the term lumbar region is more commonly used to describe a similar, though not identical, area of the body. This part of the body includes the major psoas muscle, a large muscle that is used for example when one is sitting up or bending down and is also involved in hip movement. The lumbar vertebrae, numbered as L1-L5, are also located in the loin area. Back pain is often located in this part of the spine because it carries most of the body's weight.

Pain in the loins is commonly caused by problems related to the kidneys, such as kidney stones.
Pain in the loins is commonly caused by problems related to the kidneys, such as kidney stones.

Even though the word loin is not commonly used as an anatomical term in medicine, the word is included in the names of some disorders, for example loin pain hematuria syndrome. The two main symptoms of this syndrome are pain in the loins and blood in the urine. It is not fully understood what causes the pain associated with this syndrome, but it is thought to be related to the kidneys.

Blood in the urine is one sign of loin pain hematuria syndrome.
Blood in the urine is one sign of loin pain hematuria syndrome.

Pain in the loins is commonly caused by problems related to the kidneys, such as kidney stones and renal colic, or by problems related to the ureter, meaning the tubes that carry urine from the kidneys to the bladder. The reason for this is that the nerves from the ureter enter the spinal cord in the lumbar region. Other causes of pain in the loins are injuries to the muscles or vertebrae in the lumbar region, herpes zoster, and radiculitis, a type of nerve pain that often affects the sciatic nerve.

Common Causes of Loin Pain

Discussed above were a few causes and conditions concerning loin pain, but this section will dive deeper into the many common causes of loin discomfort and pain. 

"Loin" is sometimes a euphemism for the male reproductive organs.
"Loin" is sometimes a euphemism for the male reproductive organs.

Kidney Stones: Kidney stones are probably the most common culprit of loin and abdominal pain. Kidney stones are a small build-up of calcium, minerals, and salt in the urinary tract. They can be extremely painful. They can typically pass through urination but sometimes require surgery. When you need surgery to remove a stone, it’s called Renal Colic. 

Kidney Infection: A kidney infection occurs when a UTI travels backward to the kidneys, causing the infection to spread, and can be highly painful in your lower torso area. 

Kidney Abscess: A kidney abscess is the formation of a pocket of pus inside the kidney tissue. It often occurs after a UTI or kidney infection. 

Dehydration: Dehydration can also lead to loin pain, as your organs, especially the kidney and liver, are not receiving enough water to function. If you experience loin pain, ensure you hydrate well and often. 

Tietze’s Syndrome: This syndrome is an inflammatory disorder that occurs in the torso. While it typically affects the upper rib cage and shoulders, it can also travel to the lower ribs and cause pain in the loin and pelvic area. 

Arthritis: Pelvic arthritis can cause chronic pain in the loin. People usually feel this pain most severely on the sides of their loin around their hips, but it can also cause back pain. 

Spinal Fracture: A spinal fracture, anywhere along the spine, not just toward the bottom, can lead to loin pain. A fracture often causes a ripple of pain and discomfort throughout the back and can easily affect the abdominal and loin area. 

Disc Disease: Disc disease is a degenerative disease where you lose cushioning between your vertebrae, causing pain with any movement. 

Pinched Nerve in the Back: A pinched nerve can happen when you apply too much pressure to a nerve around bones, cartilage, muscles, or tendons. If near the pelvic region, it will cause loin pain and discomfort. 

Less Common Causes of Kidney Pain

The conditions and causes discussed below are less common than the ones mentioned in the previous section. However, loin pain can still be due to the medical issues below, and it's helpful to be aware of them. 

Loin Pain Hematuria Syndrome: The syndrome’s definition details that it includes periods of severe intermittent, persistent unilateral, or bilateral loin pain. This pain also comes with either microscopic or gross hematuria.

Pneumonia: Pneumonia, and infection of the lungs, can sometimes cause loin pain. This pain is a rare symptom of pneumonia, leading many to misdiagnose the cause of the loin pain. 

Pancreatitis: Pancreatitis occurs when enzymes or digestive juices accidentally attack the pancreas, leading to redness and inflammation.

Appendicitis: Appendicitis is when the appendix ruptures, located in the loin area. 

Inflammatory Bowel Disease: Bowel diseases, such as Crohn’s Disease, can sometimes cause loin pain.

Shingles: Shingles are a form of the chickenpox virus, so anyone who ever had chickenpox can develop shingles later in life. It’s commonly associated with painful rashes but can also cause loin pain. 

Renal Infarct: This occurs when a blood clot blocks the blood supply to the kidney, resulting in pain in the kidney area. 

Abdominal Aortic Aneurysm: This condition is rare but life-threatening. It occurs when a bulge forms in the main artery supplying blood to your belly, pelvis, and legs. 

Diagnosing Loin Pain

The problem with loin and flank pain is that it can be difficult to pinpoint the cause and treat the pain. As mentioned, some viruses and infections can cause loin pain unexpectedly, like shingles and pneumonia. 

Therefore, diagnosing the cause of loin pain can take a long time and typically requires X-rays, such as an abdominal CT scan or ultrasounds. Doctors also frequently run blood tests to check the health of the kidneys. 

Urine tests are also a helpful method for finding the problem, either via a urinalysis or a urine culture. 

And lastly, they may perform a cystoscopy. This method is a minor procedure where the doctor inserts a thin tube up the urethra and into the bladder to check for signs of kidney stones, inflammation, or infection.

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Our Editorial Team, made up of seasoned professionals, prioritizes accuracy and quality in every piece of content. With years of experience in journalism and publishing, we work diligently to deliver reliable and well-researched content to our readers.
Editorial Team
Editorial Team
Our Editorial Team, made up of seasoned professionals, prioritizes accuracy and quality in every piece of content. With years of experience in journalism and publishing, we work diligently to deliver reliable and well-researched content to our readers.

Discussion Comments

umbra21

@pleonasm - That's a good suggestion for a pork loin roast. Personally, I love cooking pork loin chops with apples.

It's kind of fatty though, so I only do it once in a while.

You buy some pork chops, fry them up in a pan, then take them out and throw in some peeled and chopped apples and cook them, then remove them as well.

I like to return the chops to the pan for a little while, so they get a kind of glaze, then you can cook the drippings into sauce if you like.

Then I either serve just as it is, or sometimes chop up the apples and add some herbs or spices to them.

pleonasm

All I know about the loin is that it's the area in the cow that's called the "rump" in countries that use the British style of butchery.

But it's a pretty large area, actually. It includes most of the really good cuts of meat too, like the filet and the tenderloin.

Of course, if you are talking about pork loin, that's a really nice cut of meat for roasting.

If you get a boneless pork loin and rub it with oil and maybe some herbs and garlic, then put it in a roasting bag and stick it in the oven for a couple of hours it comes out beautiful. You can roast some potatoes with it for the last hour or so too.

We generally have this as our Sunday roast. It always comes out very tender and tasty.

browncoat

My mother was complaining about pain in this region for a couple of weeks, thinking she had somehow hurt her back. I didn't realize it was known as the loin (which I always associated with the genitals, just because of the way most people use the word).

It turned out she had actually developed a kidney infection and that's where the pain was coming from. It seems odd that you can so easily mistake pain from the kidneys as being back pain, but apparently a lot of people do that.

So, if you are having lower back pain and don't know why, and resting your back doesn't seem to help, you should consider investigating to see if you have a kidney infection.

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    • Doing a lunge can help stretch the psoas muscle, which is related to the loin.
      By: Dana Heinemann
      Doing a lunge can help stretch the psoas muscle, which is related to the loin.
    • Pain in the loins is commonly caused by problems related to the kidneys, such as kidney stones.
      By: airborne77
      Pain in the loins is commonly caused by problems related to the kidneys, such as kidney stones.
    • Blood in the urine is one sign of loin pain hematuria syndrome.
      By: tomschoumakers
      Blood in the urine is one sign of loin pain hematuria syndrome.
    • "Loin" is sometimes a euphemism for the male reproductive organs.
      By: pankajstock123
      "Loin" is sometimes a euphemism for the male reproductive organs.
    • Back pain is often located in the loin area, between the bottom of the rib cage to just below the pelvis.
      By: Laurin Rinder
      Back pain is often located in the loin area, between the bottom of the rib cage to just below the pelvis.
    • Pain in the loins may be caused by problems related to the kidneys or the ureters.
      By: 7activestudio
      Pain in the loins may be caused by problems related to the kidneys or the ureters.
    • Increasing one's intake of water may help promote the passing of kidney stones.
      By: Magdalena Kucova
      Increasing one's intake of water may help promote the passing of kidney stones.