Serotonin-norepinephrine reuptake inhibitors, or SNRIs, are a class of medications primarily used to treat depression and anxiety disorders. They work by increasing the levels of two important neurotransmitters in the brain: serotonin and norepinephrine. By preventing the reabsorption of these chemicals, SNRIs help improve mood and alleviate symptoms of anxiety. Commonly prescribed SNRIs include venlafaxine and duloxetine. These medications can also be effective for conditions like chronic pain and fibromyalgia. While generally well-tolerated, SNRIs may cause side effects such as nausea, dizziness, or changes in sleep patterns, and should be used under the guidance of a healthcare professional.