Quick mnemonics 🧠 🧂 Sodium (Na⁺) “Sodium Swells” • Sodium controls water balance in and around cells. • When sodium levels are high → water follows → fluid retention and swelling (edema) can occur. • When sodium is low → cells shrink and you can get neurological symptoms (like confusion or seizures). Mnemonic: “Sodium swells the body” → think water follows sodium! 🍌 Potassium (K⁺) “Potassium Pumps the Heart” • Potassium is essential for the electrical conduction that makes the heart beat prop