These are five common habits and factors that can impact your ability to focus:

1. Distraction
2. Insufficient sleep
3. Insufficient physical activity
4. Poor eating habits
5. Environmental factors

1. Distraction

We are bombarded by a constant flow of information, whether new or old,  during the process of doing something. Researchers have found that our brains are so primed for this distraction that just seeing our smartphone impairs our ability to concentrate. We constantly assess whether the information is useful, sufficient, or meaningless. The sheer quantity coming in muddles our assessment of whether we actually need more information to make decisions.

Insufficient sleep

Scientists have found that lack of sleep can lead to lower alertness, slower thought processes, and reduced concentration. You will have more difficulty focusing your attention and may become confused. As a result, your ability to perform tasks especially relating to reasoning or logic can be seriously affected. Chronically poor sleep further affects your concentration and memory. Dr. Allison T. Siebern from the Stanford University Sleep Medicine Centre notes that if you cannot concentrate on what is at hand, it is unlikely to make it to either your short- or long-term memory. 

3. Insufficient physical activity

Have you ever noticed how vigorous exercise leaves you feeling more relaxed and energetic throughout the day? When you don’t do physical activity, your muscles can become tense. You may feel tightness in your neck, shoulder, and chest and such persistent, low-level discomfort can affect your concentration. 

4. Poor eating habits

 What we eat contributes to how we feel, including our mental sharpness and clarity, throughout the day. If we don’t fuel our brains with the proper nutrients, we start to experience symptoms like memory loss, fatigue, and lack of concentration. Low-fat diets can ruin focus because the brain needs certain essential fatty acids. Other restrictive diets may negatively affect concentration by not providing the nutrients the brain needs or by creating hunger, cravings, or feeling of unwellness in the body that are themselves distracting. 

5. Environmental factors

Depending on what you are doing, the environment can affect your focus. Obviously, a noise level that is too loud is a problem, but many people also have difficulty concentrating when it is too quiet. It isn’t just the overall noise level but the type of noise that matters: the high-energy, anonymous hum of a coffee shop might bring focus while the overheard conversation of two co-workers derails it. A favorite song quickly has you singing along, happily distracted, while less distinct instrumentals might keep you attuned to the task. Lighting that is too bright or too dim can affect your vision. A room that is too hot or too cold creates discomfort.

All of these elements can affect your concentration. Happily, they are also all addressable.

Conditions related to concentration

If you frequently can’t focus your thoughts and are experiencing ongoing concentration difficulties, it may indicate a cognitive, medical, psychological, lifestyle, or environmental cause. Depending on the cause, you may have to temporarily accept that your concentration is low and learn a few tricks to reduce the impact or accept the dips as they come. If you need help with concentration and think your difficulties go beyond the list above, consult with a professional. 

Possible broader conditions include:

• Cognitive. Your concentration may decrease if you find yourself forgetting things easily. Your memory sometimes fails you, you misplace articles, and have difficulty remembering things that occurred a short time ago. Another way your concentration may be cognitively impaired is if you find that your mind is overactive, constantly thinking of multiple things due to concerns or important events. When thoughts and issues intrude into your mind, demanding attention, it prevents effective concentration. 
• Psychological. When you are depressed and feeling down, it is difficult to focus. Similarly, when you are recovering from the loss of a loved one during bereavement or are experiencing anxiety, you may have difficulty focusing on a single task.
• Medical. Medical conditions like diabetes, hormonal imbalances, and low red blood cell count can affect our concentration. Some medication also makes you drowsy or bleary and severely impair concentration.  
• Environmental. Poor working conditions, shared spaces, and intense or negative work dynamics may also contribute to a lack of concentration. When we are experiencing burnout or stress from work or personal life, we will find it difficult to concentrate due to emotional exhaustion. Similarly, the environment can create discomfort to our body with effects that we’re aware of (heat, light, noise) and others that don’t fully register (tension, negativity, monitoring).
• Lifestyle. Fatigue, hunger, and dehydration can derail concentration. Lifestyles that involve too many missed meals, rich foods, or excessive alcohol consumption can challenge our memory and ability to concentrate and focus.