Definition of kidney stones

Kidney stones are solid masses of crystals which tend to form inside the kidneys, their constituents include minerals and salts. Stones can also form in the ureters, bladder, and urethra.

While nephrolithiasis refers to stones inside the kidneys, Urolithiasis are stones that tend to originate anywhere in the urinary system (including the kidneys, both ureters, bladder, and urethra).

If you are a person with a kidney stone, you are not alone; it is estimated that 10% of all people tend to have a kidney stone at some point in their lives. Since the condition seems to be quite common, let's dive in to get more details about it!

Signs and symptoms

The most common symptom people associate with having kidney stones is intense pain in the back and flank. The pain occurs as the stone passes through the ureter; thus, it stimulates nerve endings that result in experiencing pain.

Passing a kidney stone is considered to be one of the most painful conditions someone can experience; some patients tend to describe the pain they experience as an unbearable pain that comes at irregular intervals (intermittent).

Some other symptoms include:

• Blood in your urine (hematuria)
• A burning sensation while urinating
• Nausea & Vomiting
• Fever
• Urine that smells bad or seems cloudy

Stones that are located in the middle part of the ureter can produce symptoms of other diseases.

For example, if the stone is on the right side, it can imitate abdominal pain of appendicitis; if it is on the left side, it can imitate abdominal pain of diverticulitis (infection of diverticula, which commonly happens on the left side).

When the kidney stone finally approaches the bladder, it manifests bladder symptoms such as urinary frequency, Painful urination (dysuria), pain in the lower abdomen, and urinary incontinence.

Formation & causes of kidney stones

Generally speaking, Kidneys stones are formed when the concentration of certain types of substances {like calcium (Ca), sodium (Na), potassium (K), oxalate (CO ^-2), uric acid and phosphate (PO₄^-3)} build up. Urine naturally contains these substances, but these substances can aggregate and form crystals when their concentration gets too high (or if urine becomes too acidic or basic).

There are a couple of causes that increase the likelihood of stone formation:

1. Certain medical conditions (e.g., Crohn's disease, hyperparathyroidism…) can lead to an unusually high level of chemicals (that lead to stone formation) in your urine.
2. Not drinking enough water or other fluids.
3. Taking certain types of medications, for example, Some over-the-counter (OTC) drugs such as ephedrine (as a stimulant and for weight reduction) contribute to the formation of drug-induced kidney stones.
4. Genetic factors

(Note: only in very rare cases some stones can result from genetic disorders or certain medications)

If the situation is left unaddressed, these small crystals tend to gradually grow over time, thus forming a larger stone that can cause discomfort and the intense pain that is associated with kidney stones.

Types of kidney stones

There are 4 main types of stones:

1. Calcium stones: as their name suggests, these stones contain calcium; calcium oxalate, for instance, is the most common type of all kidney stones and accounts for about 80% of kidney stones.
2. Uric acid stones: high urine acidity (Ph below 5.5) and high uric acid concentration contribute to the formation of these stones.
3. Cystine stones
4. Struvite stones: also called infection stones, make up a small percentage of all kidney stones, tend to form when there is a urinary tract infection. It is important to mention that the agent which has caused the infection is not directly responsible for stone formation; rather, the formation occurs due to the changes in the environment of the urinary tract.