Pick what you're seeing. We'll show you the likely cause and how to fix it.
Mushy leaves · Most likely cause
Soft, mushy leaves mean the plant has taken up more water than it can use, or the roots have started to rot in wet soil.
Wrinkled leaves · Most likely cause
Wrinkled, deflated leaves usually mean the plant has used up its stored water. Check the soil first, because wet soil changes the answer.
Stretching · Most likely cause
Growth that's pale, stretched and leaning toward the window means the plant isn't getting enough light. Gardeners call it etiolation.
White fluff · Most likely cause
White, cottony fluff tucked between leaves or along stems is usually mealybugs, a small sap-sucking insect.
Leaves falling off · Most likely cause
Leaves that drop at a touch are usually a water problem. Whether they're plump or shriveled when they fall tells you which way.
Nearly every struggling succulent comes down to one of three things: too much water, too little light, or a pest. Water is the big one. Succulents store water in their leaves, so wet soil that never dries out rots the roots long before you see a problem above ground.
Start with the soil. If it's wet and the leaves are soft, it's overwatering. If it's bone dry and the leaves are wrinkled, it's thirst. If the plant is pale and stretching toward the window, it needs more light.