Uric acid is the result of the metabolic breakdown of purine nucleotides and is a normal component of urine. Purines are found in many different types of foods including:

• Meat & meat products
• Fish
• Beer
• Spinach
• Cauliflower
• Green peas
• Lentils

When it comes to kidney stones, uric acid stones almost always form in individuals with abnormally acidic (low pH) urine. Abnormally acidic urine is commonly found in people suffering from obesity, diabetes, gout, or kidney disease. Uric acid kidney stones represent roughly 15% of the kidney stones formed. 

Molecularly, uric acid is made up of two linked rings of carbon atoms (grey), with nitrogen (blue) , oxygen (red), and hydrogen (white) atoms inserted amongst them (see below).

As we have discussed in previous blogs about Calcium Oxalate Kidney Stones and Calcium Phosphate Kidney Stones, urine pH has a significant influence over stone formation. Urine pH has the power to either positively or negatively impact available charge sites on a molecule (a.k.a. where other particles can bind to the molecule). In uric acid’s case, the molecule has two charge sites located at the Nitrogen atom that are subject to being influenced. 

In urine of a neutral ph (~6), one of the nitrogen atoms (blue) lacks its hydrogen atom (white) and therefore carries a single negative charge (See Figure B below). In more alkaline urine (pH of greater then 8), both nitrogens lack their hydrogen atoms (white) (see Figure C below). However, urine very rarely hits this level of alkalinity. 

Urine with a low pH (less than 5.5) presents a situation where both nitrogens (blue) have their hydrogens (white) and the molecule lacks any charge site (see Figure A above). This sounds like it might be a good thing; however, it is a problem, as it does not leave any charge site open for water (H2O) to bind with the molecule. Since there is no way for water to bind with the molecule to flush the uric acid out of the system, the molecule crystalizes and stacks into solid crystals. Thus, we start to see the formation of uric acid kidney stones. 

The resulting crystals/stones are red or orange in color (see below). This is because the uric acid crystals absorb hemoglobin breakdown products that are red or orange pigments in the urine (hemoglobin is a protein in red blood cells that carries oxygen throughout the body). It is not uncommon for uric acid crystals to pass in urine as red or orange gravel.

Unlike calcium oxalate or calcium phosphate stones, uric acid does not have to bind itself with another atom or molecule to make a crystal. When urine pH is low enough to eliminate its two charge sites, uric acid crystals can form at an alarming rate (in seconds). 

In most situations, the rapidly formed crystals are merely passed as orange gravel in the urine. However, if the crystals are retained, the crystals can grow rapidly into large stones. And, since there is much more uric acid in the urine than there is oxalic acid, uric acid stones can grow very large and very quickly. Some fill up the entire collecting system of the kidney (see below).

Fortunately, for those of us who suffer from uric acid kidney stones, this type of stone is very easy to treat. Adding a modest amount of supplemental alkali daily will render the urine of almost any individual alkaline enough to stop uric acid stones from forming. This is because when urine is alkalized, one of the hydrogen atoms (white) is removed from the molecule, opening up one of the critical charge sites. Water now has the ability to bond with the molecule at the open charge site (think of a magnetic situation here) and flush the uric acid molecule out of the body... provided you hydrate yourself properly. Because treatment for this stone type is so simple and definite, relapse need not ever occur. 

But, what do we mean by supplemental alkali? Well, this can come in a few different forms. One in particular that is readily available is potassium citrate, which can be found in most pharmacies and online. It is most often found in tablet form.

However, there are better and more bioavailable sources of citrate that we encourage you to look into. For example, simply adding the juice of 1 whole lemon (we suggest organic) to water each day will more than suffice. This is why we use raw lemon in our Stone Relief herbal tea and capsules. Additionally, Chanca Piedra (as we discussed in our last blog HERE), naturally boosts citrate in urine. Thus, providing an additional layer of protection for uric acid stone formers. 

Either way you attack it, uric acid stones are simple, easy, and fast to fix.