Water Retention Is Not One Problem. It Is Eight.

By Tina Chagoury, Clinical Dietitian · 5 min read · 2026-08-21

Water retention has one name and at least eight causes. It is a signal that something in the body is out of balance, and it is worth knowing which thing.

Let me define water retention simply, so that all of its causes make sense.

Water retention is the accumulation of fluid in your tissues. It happens when water moves out of the blood vessels and collects in the body.

You recognise it as puffiness, swelling, a ring that suddenly will not go over your finger, clothes that feel tighter, and a number on the scale that shifts without any real change in body composition.

Here is the part that matters. Water retention almost never comes from one system. It comes from several, interacting.

1. Inflammation

This is the primary cause. Inflammation makes your blood vessels more permeable, which is to say leakier. Water escapes from the vessels and collects in the tissues. If you want one indicator of chronic low grade inflammation in the body, this is it.

2. Hormonal changes

Particularly oestrogen and progesterone, in the days before your period or throughout perimenopause. This is why so many women swell predictably at the same point in the cycle.

3. Stress and cortisol

Cortisol affects aldosterone, the hormone that governs the balance of water in the body. Elevated cortisol increases sodium retention, and water follows.

4. Blood sugar and insulin

Insulin causes the kidneys to hold onto sodium. Unstable blood sugar therefore produces visible fluid retention, which is why so many women wake up puffy after a heavy carbohydrate evening.

5. Poor circulation or lymphatic drainage

The lymphatic system has no pump of its own. It depends on movement. A sedentary day is a day of poor drainage.

6. Gut inflammation

Inflammation in the gut raises inflammation everywhere. The two are not separable.

7. Salt without balance

High sodium intake matters far less on its own than high sodium combined with low potassium. It is the ratio that counts, not the salt shaker.

8. Dehydration

This is the one that surprises people. When you are underhydrated, the body holds onto water more tightly, as a protective response. Drinking more water frequently reduces retention rather than increasing it.

What this means practically

Water retention is not a condition to be treated with a diuretic and forgotten. It is a signal that something is out of balance, and the useful question is always: which of these eight, and in what combination?

In practice, the highest yield places to start are:

• Reduce the inflammatory load. Processed food, refined oils, fried food and excess sugar.
• Stabilise blood sugar. Protein at every meal, no constant grazing.
• Move. Walking, resistance training, anything that drives lymphatic drainage.
• Hydrate properly. Genuinely, consistently, all day.
• Balance sodium with potassium. Vegetables do this for you.
• Address stress honestly, because cortisol is not negotiable through willpower alone.

If your retention is cyclical, track it against your cycle. If it is constant, it is worth investigating inflammation, thyroid function and gut health properly.

This article is nutrition education, not medical advice. Sudden or one sided swelling should always be assessed by a doctor.

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About the author. Tina Chagoury is a licensed clinical dietitian specialising in women's hormonal health, inflammation and gut health, and the creator of the Hormone Reset Method™. Learn more about the Hormone Reset Method.