Water the plant immediately and keep its soil and compost moist all the time. If you already have a regular watering schedule and it doesn’t solve the problem, check the water. If you’re living in an area with hard water, consider using distilled water or rainwater. Hard water can cause the soil to turn alkaline and can prevent the plant from thriving. If your plant has lost more than 30% of its usual number of leaves, consider discarding it because the damage is irreversible.